Patent Publication Number: US-11382512-B2

Title: Energy transfer system for spinal implants

Description:
TECHNICAL FIELD 
     The present disclosure generally relates to a relay system for providing energy to deep tissue implants such as, for example, pedicle screws. 
     BACKGROUND 
     Treatment of spinal disorders, such as degenerative disc disease, disc herniations, scoliosis or other curvature abnormalities, and fractures, often requires surgical treatments. For example, spinal fusion may be used to limit motion between vertebral members. As another example, implants may be used to preserve motion between vertebral members. 
     Surgical treatment typically involves the use of longitudinal members, such as spinal rods. Longitudinal members may be attached to the exterior of two or more vertebral members to assist with the treatment of a spinal disorder. Longitudinal members may provide a stable, rigid column that helps bones to fuse, and may redirect stresses over a wider area away from a damaged or defective region. Also, rigid longitudinal members may help in spinal alignment. 
     Screw assemblies may be used to connect a longitudinal member to a vertebral member. A screw assembly may include a pedicle screw, hook, or other connector and/or a set screw, among other components. A pedicle screw can be placed in, above and/or below vertebral members that were fused, and a longitudinal member can be used to connect the pedicle screws which inhibits or controls movement. A set screw can be used to secure the connection of a longitudinal member and a pedicle screw, hook or other connector. 
     Inductive coupling may be used to power and/or communicate with an implant, such as for example, a screw assembly. However, inductive coupling is limited due to distance constraints with an external power source. 
     SUMMARY 
     In an embodiment, an energy transfer system includes a spinal implant having one or more antennae, and the spinal implant is configured to be positioned within a spinal area of a patient, and a relay device configured to be positioned within the patient between the implant and the skin of the patient when implanted. The relay device is configured to receive energy from a reader device located externally to the patient and convey at least a portion of the received energy to the one or more antennae of the spinal implant. 
     The relay device may be configured to receive energy from the reader device when the reader device is placed in proximity to the relay device. The relay device may be configured to receive energy from the reader device when the reader device is placed within two to three inches from the relay device. 
     The relay device may include an induction coil. 
     The relay device may be positioned within a subcutaneous pocket. 
     The implant may be positioned four inches from the skin of the patient. 
     The relay device may be positioned between a half an inch and three inches from the spinal implant. 
     The relay device may be positioned between two inches and three inches from the skin of the patient. 
     The spinal implant may include a pedicle screw having a set screw and an anchoring member. The set screw may include the one or more antennae. 
     The spinal implant may include a control unit having one or more integrated circuits or micro-electronic chips. 
     The one or more integrated circuits may include a flexible printed circuit. 
     The one or more micro-electronic chips may include a radio frequency identification chip, or a near field communication chip. 
     Optionally, the energy transfer system may include one or more antenna extenders attached to the spinal implant. 
     The spinal implant may be configured to use the at least a portion of the received energy to power the spinal implant. 
     The spinal implant may be configured to retrieve data from the received energy. 
     The relay device may be configured to receive information from the spinal implant and transfer at least a portion of the received information to the reader device. 
     In an embodiment, an energy transfer system includes a spinal implant having one or more antennae and one or more sensors. The spinal implant is configured to be positioned within a spinal area of a patient. The energy transfer system includes a relay device configured to be positioned within the patient between the implant and the skin of the patient when implanted. The relay device includes memory. The relay device is configured to receive energy from a reader device located externally to the patient and convey at least a portion of the received energy to the one or more antennae of the spinal implant. The spinal implant is configured to transmit data collected by one or more of the sensors to the relay device for storage in the memory. 
     The relay device may include a battery. The relay device may include a communications device. The one or more sensors may be configured to attach to a longitudinal member of the spinal implant. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an example anchoring assembly and longitudinal member. 
         FIG. 2  illustrates an example exploded view of a screw assembly and longitudinal member. 
         FIGS. 3A and 3B  illustrate example antenna placements for an implant. 
         FIG. 4A  illustrates an example energy transfer system for an implant. 
         FIG. 4B  illustrates an example energy transfer system for an implant. 
         FIG. 5  illustrates an example energy transfer system for an implant. 
         FIG. 6A  illustrates an example cannulated instrument driver. 
         FIG. 6B  illustrates an example cannulated instrument driver engaging an example set screw. 
         FIG. 7  illustrates an example energy transfer system for an implant. 
     
    
    
     DETAILED DESCRIPTION 
     The exemplary embodiments of the surgical system and related methods of use disclosed are discussed in terms of medical devices for the treatment of musculoskeletal disorders and more particularly, in terms of vertebral fixation screws, including for example pedicle screws, as well as hooks, cross connectors, offset connectors and related systems for use during various spinal procedures or other orthopedic procedures and that may be used in conjunction with other devices and instruments related to spinal treatment, such as rods, wires, plates, intervertebral implants, and other spinal or orthopedic implants, insertion instruments, specialized instruments such as, for example, delivery devices (including various types of cannula) for the delivery of these various spinal or other implants to the vertebra or other areas within a patient in various directions, and/or a method or methods for treating a spine, such as open procedures, mini-open procedures, or minimally invasive procedures. Exemplary prior art devices that may be modified to include the various embodiments of the energy transfer system described in this document and include, for example, U.S. Pat. Nos. 6,485,491 and 8,057,519, all incorporated herein by reference in their entirety. 
     The present disclosure may be understood more readily by reference to the following detailed description of the embodiments taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this application is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting. 
     In some embodiments, as used in the specification and including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It is also understood that all spatial references, such as, for example, horizontal, vertical, top, upper, lower, bottom, left and right, are for illustrative purposes only and can be varied within the scope of the disclosure. For example, the references “upper” and “lower” are relative and used only in the context to the other, and are not necessarily “superior” and “inferior”. Generally, similar spatial references of different aspects or components indicate similar spatial orientation and/or positioning, i.e., that each “first end” is situated on or directed towards the same end of the device. Further, the use of various spatial terminology herein should not be interpreted to limit the various insertion techniques or orientations of the implant relative to the positions in the spine. 
     The following discussion includes a description of a vertebral pedicle screw system and related components and methods of employing the vertebral pedicle screw in accordance with the principles of the present disclosure. Reference is made in detail to the exemplary embodiments of the present disclosure, which are illustrated in the accompanying figures. Although this disclosure discusses a vertebral pedicle screw as an example of a deep tissue implant, it is understood that other types of implants, such as for example, intervertebral implants, rods, braces, connectors, hooks, plates, and/or the like may be used within the scope of this disclosure. 
     One or more components of a deep tissue implant (e.g., a pedicle screw system) described herein can be fabricated from biologically acceptable materials suitable for medical applications, including metals, synthetic polymers, ceramics and bone material and/or their composites. For example, the components of an implant, individually or collectively, can be fabricated from materials such as stainless steel alloys, commercially pure titanium, titanium alloys, Grade 5 titanium, super-elastic titanium alloys, cobalt-chrome alloys, stainless steel alloys, superelastic metallic alloys (e.g., Nitinol, super elasto-plastic metals, such as GUM METAL®), ceramics and composites thereof such as calcium phosphate (e.g., SKELITE™), thermoplastics such as polyaryletherketone (PAEK) including polyetheretherketone (PEEK), polyetherketoneketone (PEKK) and polyetherketone (PEK), carbon-PEEK composites, PEEK-BaSO 4  polymeric rubbers, polyethylene terephthalate (PET), fabric, silicone, polyurethane, silicone-polyurethane copolymers, polymeric rubbers, polyolefin rubbers, hydrogels, semi-rigid and rigid materials, elastomers, rubbers, thermoplastic elastomers, thermoset elastomers, elastomeric composites, rigid polymers including polyphenylene, polyamide, polyimide, polyetherimide, polyethylene, epoxy, bone material including autograft, allograft, xenograft or transgenic cortical and/or corticocancellous bone, and tissue growth or differentiation factors, partially resorbable materials, such as, for example, composites of metals and calcium-based ceramics, composites of PEEK and calcium based ceramics, composites of PEEK with resorbable polymers, totally resorbable materials, such as, for example, calcium based ceramics such as calcium phosphate, tri-calcium phosphate (TCP), hydroxyapatite (HA)-TCP, calcium sulfate, or other resorbable polymers such as polyaetide, polyglycolide, polytyrosine carbonate, polycaroplaetohe and their combinations. 
     Various components of an implant may be formed or constructed material composites, including the above materials, to achieve various desired characteristics such as strength, rigidity, elasticity, compliance, biomechanical performance, durability and radiolucency or imaging preference. The components of an implant, individually or collectively, may also be fabricated from a heterogeneous material such as a combination of two or more of the above-described materials. The components of an implant may be monolithically formed, integrally connected or include fastening elements and/or instruments, as described herein. The components of an implant may be formed using a variety of subtractive and additive manufacturing techniques, including, but not limited to machining, milling, extruding, molding, 3D-printing, sintering, coating, vapor deposition, and laser/beam melting. Furthermore, various components of an implant may be coated or treated with a variety of additives or coatings to improve biocompatibility, bone growth promotion or other features. To the extent the plate is entirely or partially radiolucent, it may further include radiographic markers made, for example of metallic pins, at one or both ends, on each corner of the ends, and/or along the length of the implant in various locations including near the center of the assembly. 
     An implant may be employed, for example, with a minimally invasive procedure, including percutaneous techniques, mini-open and open surgical techniques to deliver and introduce instrumentation and/or one or more implants at a surgical site within a body of a patient, for example, a section of a spine. In some embodiments, an implant may be employed with surgical procedures, as described herein, and/or, for example, corpectomy, discectomy, fusion and/or fixation treatments that employ spinal implants to restore the mechanical support function of vertebrae. In some embodiments, an implant may be employed with surgical approaches, including but not limited to: anterior lumbar interbody fusion (ALIF), direct lateral interbody fusion (DLIF), oblique lateral lumbar interbody fusion (OLLIF), oblique lateral interbody fusion (OLIF), various types of anterior fusion procedures, and any fusion procedure in any portion of the spinal column (sacral, lumbar, thoracic, and cervical, for example). In some embodiments, an implant may be employed with posterior lumbar interbody fusion (PLIF), midline posterior techniques, posterolateral techniques, and/or other posterior techniques. In some embodiments, an implant may be employed for the treatment of spinal disease and/or deformity conditions including, without limitation, scoliosis, spondylolisthesis, and/or the like. 
       FIG. 1  illustrates an example implant  10  having an anchoring assembly and longitudinal member according to an embodiment. As illustrated in  FIG. 1 , an anchoring assembly includes a screw  20  and an anchoring member  30 . The screw  20  has an elongated shape with a first end mounted within a vertebral member  200  and a second end extending outward above the vertebral member  200 . The anchoring member  30  is configured to operatively connect to the second end of the screw  20  and is movably connected to the screw  20  to accommodate the longitudinal member  100  positioned at various angular positions. The anchoring member  30  includes a channel  31  sized to receive the longitudinal member  100 . A set screw  50  attaches to the anchoring member  30  to capture the longitudinal member  100  within the channel  31 . 
       FIG. 2  illustrates an example exploded view of a screw assembly and longitudinal member according to an embodiment. As shown by  FIG. 2 , anchoring member  30  provides a connection between the screw  20  and longitudinal member  100 . Anchoring member  30  includes a first end  32  that faces towards the vertebral member  200 , and a second end  33  that faces away. A chamber is positioned between the first and second ends  32 ,  33  and is sized to receive at least a portion of the screw  20 . In various embodiments, a first end  32  may be considered a base portion of an anchoring member  30 , and a second end  33  may be considered a head portion of an anchoring member. 
     The second end  33  of the anchoring member  30  includes a channel  31  sized to receive the longitudinal member  100 . Channel  31  terminates at a lower edge  38  that may include a curved shape to approximate the longitudinal member  100 . Threads  37  may be positioned towards the second end  33  to engage with the set screw  50 . In one embodiment as illustrated in  FIG. 2 , the threads  37  are positioned on the interior of the anchoring member  30  facing towards the channel  31 . In another embodiment, the threads  37  may be on the exterior of the anchoring member  30 . An interior of the anchoring member  30  may be open between the first and second ends  32 ,  33 . 
     In various embodiments, an anchoring member  30  may include a washer  60 . A washer  60  may be generally cylindrical and may have a hole  66  therethrough. As illustrated by  FIG. 1  a washer  60  may be positioned near a first end  32  of an anchoring member  30 . A screw  20  may engage with an anchoring member  30  via positioning through the hole  66  of a washer  60 . A washer  60  may include recessed portions which may be configured to accommodate placement of a longitudinal member  100  therein. The use of a washer  60  in connection with an anchoring member  30  may help minimize misalignment of the longitudinal member within the anchoring member. 
     In an embodiment, set screw  50  attaches to the anchoring member  30  and captures the longitudinal member  100  within the channel  31 . As illustrated in  FIG. 2 , the set screw  50  may be sized to fit within the interior of the channel  31  and include exterior threads  51  that engage threads  37  on the anchoring member  30 . A driving feature  52  may be positioned on a top side to receive a tool during engagement with the anchoring member  30 . In some embodiments, the set screw  50  may be mounted on an exterior of the anchoring member  30 . Set screw  50  includes a central opening and is sized to extend around the second end  33 . A set screw  50  may be a break-off set screw or a non-break-off set screw. In certain embodiments, a set screw  50  may include a slot for receiving or routing of electronic connections. Threads  51  are positioned on an inner surface of the central opening to engage with the external threads  37  on the anchoring member  30 . The set screw  50  and anchoring member  30  may be constructed for the top side of the set screw  50  to be flush with or recessed within the second end  33  when mounted with the anchoring member  30 . 
     In various embodiments, an implant may have one or more antennas.  FIG. 3A  illustrates an example set screw  50  having an antenna  300  positioned on an external portion of the set screw.  FIG. 3B  illustrates an example set screw  50  having an antenna  300  positioned internally in a central opening of the set screw. Examples of an antenna  300  include, without limitation, a radio frequency identification (RFID) coil, a near field-communication (NFC) antenna or other short-range communication transmitter and/or receiver. Examples of antennae and example placements are described in U.S. patent application Ser. No. 16/395,221, filed Jul. 3, 2019, the contents of which are incorporated into this disclosure by reference it its entirety. 
     In various embodiments, an implant may include a control unit. A control unit may be part of a set screw, anchoring member, and/or the like. A control unit may include one or more integrated circuits or micro-electronic chips for powering implant and/or detecting/sensing diagnostics. Examples of integrated circuits or micro-electronic chips include, without limitation, an RFID chip, an NFC chip, and/or the like. In another embodiment, an integrated circuit may include a custom radio frequency communication scheme or protocol. An integrated circuit may include one or more components for powering the implant and/or detecting/sensing diagnostics, and is suitable for implantation. In some embodiments, an integrated circuit may include, for example, a flexible printed circuit. 
     In certain embodiments, an integrated circuit may transmit one or more measurements to the reader device. This transmission may occur in response to being interrogated by the reader device, or the transmission may be initiated by the integrated circuit. The reader device may receive the transmitted measurements, and may cause at least a portion of the measurements to be displayed to a user. For instance, a physician may use a reader device to interrogate a patient&#39;s implant. The reader device may include a display, or may be in communication with a display device, which may display at least a portion of the measurements received from the implant. 
     An integrated circuit may be passive, meaning that it has no internal power source and is powered by the energy transmitted from a reader device. With respect to an assembly having a passive integrated circuit, the integrated circuit may not transmit information until interrogated by a reader device. 
     In another embodiment, an integrated circuit may be active, meaning that the chip is battery-powered and capable of broadcasting its own signal. An active integrated circuit may transmit information in response to be interrogated by a reader device, but also on its own without being interrogated. For instance, an active integrated circuit may broadcast a signal that contains certain information such as, for example, one or more measurements gathered by an implant. An active integrated circuit may continuously broadcast a signal, or it may periodically broadcast a signal. Power may come from any number of sources, including, for example, thin film batteries with or without encapsulation or piezo electronics. 
     In some embodiments, the control unit may remotely communicate with electronic components disposed outside or external to a body of a patient. For instance, a control unit may include one or more transmitters and/or receivers for facilitating wireless communication with electronic components disposed outside or external to a body of a patient. In some embodiments, the control unit may remotely communicate with such external electronic components to power implant and/or transfer, transmit and/or receive data relating to implant including treatment and/or diagnostics, as described herein. In some embodiments, the remote communication can include a wireless link, such as, for example, Bluetooth, NFC, WiFi, MICS, and/or as described in U.S. Pat. No. 5,683,432 “Adaptive Performance-Optimizing Communication System for Communicating with an Implantable Medical Device” to Goedeke, et al., the contents of which being hereby incorporated by reference in its entirety. 
     A control unit may communicate with an external electronic device such as, for example, a reader device. For example, an RFID chip may be read by an RFID reader. As another example, an NFC chip may be read by or may otherwise communicate with an NFC reader or other NFC-enabled device. A reader device may interrogate an integrated circuit when in placed within a certain distance to the integrated circuit. In other embodiments, an integrated circuit may communicate with a reader or other electronic device without being interrogated. 
       FIG. 4A  illustrates an example energy transfer system for an implant according to an embodiment. As illustrated by  FIG. 4A , the system  400  may include an implant  402 , a relay device  404 , and a reader device  406 . As illustrated in  FIG. 4A , an implant  402  may have one or more antennae  408  and a control unit  410 . The control unit  410  may be positioned within at least a portion of a set screw of a pedicle screw assembly according to an embodiment. Alternate positions of a control unit  410  may be used within the scope of this disclosure.  FIG. 4A  illustrates the implant  402  as a pedicle screw assembly. However, it is understood that additional and/or alternate types of implants may be used within the scope of this disclosure. 
     In various embodiments, a relay device  404  may be a transfer coil such as, for example, an induction coil. A relay device  404  may be fabricated from an electrical conductor such as, for example, wound copper. In various embodiments, a relay device may include a ferrite core, which may help to increase absorption of energy. Additional and/or alternate materials may be used within the scope of this disclosure. 
     A relay device  404  may wirelessly receive energy from a reader device  406 , and may transfer at least a portion of the received energy to an antenna of an implant  402 . In various embodiments, the received energy may include data. Similarly, a relay device  404  may receive data from an antenna  408  of an implant, and transfer at least a portion of the received data to a reader device  406 . As such, a relay device  404  may act as a relay between a reader device  406  and an implant  402 . In this way, a relay device  404  may bridge distance constraints between an implant  402  and an external power supply. In various embodiments, a reader device  406  may transfer energy to a relay device  404  when positioned within two to three inches from the relay device. 
     A relay device  404  may be positioned in a subcutaneous pocket  412  of a patient. The subcutaneous pocket  412  may be surgically created. In various embodiments, a relay device  404  may be positioned in subcutaneous pocket  412  that is located in proximity to an implant  402 . For example, a relay device  404  may be positioned within a half an inch to three inches from an implant  402 . Alternate distances or ranges of distances may be used within the scope of this disclosure. As another example, a relay device  404  may be positioned approximately halfway between an implant  402  and the surface  414  of a patient&#39;s skin. Additional and/or alternate placements and/or spacing of a relay device are within the scope of this disclosure. 
     In various embodiments, an implant  402  may be positioned approximately four inches below the skin of a patient. The distance between an implant  402  and a relay device  404  may be between a half an inch and three inches. The distance between a relay device  404  and a patient&#39;s skin may be approximately two to three inches. It is understood that alternate distances or ranges of distances may be used within the scope of this disclosure. 
     The reader device  406  may serve as a remote power source disposed outside or external to a body of a patient. The control unit of an implant  402  may be configured for inductive communication with the reader device  406  for power harvesting of a communication signal for powering implant. In some embodiments, reader device may include or be a component of a computer, a tablet, a smartphone, a cell phone, PDA, laptop, surgical instrument, clothing, accessory and/or other device. 
     The reader device  406  may emit a small electric current to create a magnetic field that bridges the physical space between the reader device and implant  402  implanted within a patient. The reader device  406  radiates energy through a cutaneous barrier, such as, for example, the skin  414  of a patient adjacent to the implant  402 . An electromagnetic field may be generated by the reader device  406  (e.g., a transmitting coil) to transmit power across the skin  414  to the control unit of the implant  402 . The control unit  410  may use the received energy to power or charge the implant  402 . The received energy may include data being transmitted to the implant. The control unit  410  may receive the data from the energy. In various embodiments, the implant  402  may send data to the reader device  406 . For example, the implant  402  may send data via one or more antennae of the implant to the relay device  404 . The relay device  404  may in turn transmit the data to the reader device  406 . 
     In some embodiments, the control unit  410  may include diagnostic sensor electronics connected with one or more sensors disposed about an implant to obtain and store data received from implant and surrounding tissue. Diagnostic sensor electronics may comprise various commercially available integrated circuit devices, see, for example, but not limited to, the AD5933 Impedance Converter Network Analyzer distributed by Analog Devices. Integrated circuit device may comprise various commercially available integrated circuit devices, see, for example, but not limited to, the RF430 microcontroller distributed by Texas Instruments RF430. 
       FIG. 4B  illustrates an alternative embodiment of an example energy transfer system for an implant according to an embodiment. As illustrated in  FIG. 4B , a relay device  404  may include a battery  416 . The battery  416  may be inductively powered or charged by an external device such as, for example, a reader device  406 . A relay device  404  may include memory  418  and/or a communication device  420 . A communication device  420  may facilitate communication, such as wireless communication, between the relay device  404  and one or more other devices disposed within or outside of the body of a patient. Examples of a communication device  420  may include, for example, an antenna, a receiver, a transmitter, a transceiver, an NFC chip, an RFID chip, and/or the like. 
     A reader device  406  may emit a small electric current to create a magnetic field that bridges the physical space between the reader device and relay device  404 . The reader device  406  radiates energy through a cutaneous barrier, such as, for example, the skin  414  of a patient adjacent to the relay device  404 . An electromagnetic field may be generated by the reader device  406  (e.g., a transmitting coil) to transmit power across the skin  414  to the relay device  404 . The battery  416  of the relay device  404  may use the received energy to power or charge the relay device. The relay device  404  may transmit power to the implant  402 . The received energy may include data being transmitted. The relay device  404  may receive the data from the energy. In various embodiments, the relay device  404  may send data to the reader device  406  and/or the implant  402 . For example, the implant  402  may send data via one or more antennae of the implant to the relay device  404 . The relay device  404  may in turn transmit the data to the reader device  406 . 
     In various embodiments, data recorded by an implant  402  may be stored in the memory  418  of a relay device  404 . This may allow extended recording of data from an implant  402  which may be downloaded at some future time such as, for example, at an office visit. 
     In various embodiments, a relay device  404  may be used in conjunction with an implant device  402  having one or more sensor devices  422 . A sensor device  422  may include a battery  424  and or more sensors  426 . A sensor device  422  may be configured to attach to a portion of an implant  402 , such as, for example, a longitudinal member. A battery  424  of a sensor device  422  may be powered by a battery  416  of the relay device  404 . The sensors  426  of a sensor device  422  may include, for example, a tri-axial accelerometer, a tri-axial gyroscope and/or the like. A sensor device  422  may collect data from one or more of its sensors  426  and may transmit at least a portion of this data to a relay device  404 . The relay device  404  may store at least a portion of the received data in its memory  418 . This data may be downloaded and/or otherwise transmitted from the relay to an external device. 
       FIG. 5  illustrates an example energy transfer system for an implant according to an embodiment. As illustrated by  FIG. 5 , the system  500  may include an implant  502  and a reader device  508 . As illustrated in  FIG. 5 , an implant  502  may have one or more antennae  504  and a control unit  506 . One or more of the antennae  504  may include an antenna extender  506  according to an embodiment.  FIG. 5  illustrates the implant  502  as a pedicle screw assembly. However, it is understood that additional and/or alternate types of implants may be used within the scope of this disclosure. 
     An antenna extender  506  may be fabricated from a flexible, dielectric material such as, for example, a silicon substrate. The composition and flexible nature of an antenna extender  506  may reduce the risk that a patient will experience tissue irritation post operation. 
     An antenna extender  506  may be attached at a proximal end to a portion of an implant  502  that is in proximity to an antenna  504 . For example, as illustrated by  FIG. 5 , an antenna extender may be attached to a set screw near a distal end of the set screw. An antenna extender may be attached to an implant in any suitable manner including, without limitation, laser welding. 
     A distal end of an antenna extender  506  may extend away from an implant  502 , and toward the skin  510  of a patient. As such, the use of an antenna extender  506  may help to reduce the distance between the implant  502  and a reader device  508 . 
     In various embodiments, as illustrated by  FIG. 5 , an implant  502  may include more than one antenna extender  506 . For instance, referring to  FIG. 5 , an implant includes two antennae  504 . An antenna extender  506  may be attached in proximity to each antenna. Although  FIG. 5  illustrates the use of multiple antenna extenders  506 , it is understood that more or fewer antenna extenders may be used within the scope of this disclosure. 
     In various embodiments, an antenna extender  506  may have a diameter that is compatible with a cannulated instrument driver. A cannulated instrument driver may be a tool having a cannula. A cannulated instrument driver may be used to position an implant or an implant component within a patient. 
     The length of an antenna extender may be between a half an inch and three inches in various embodiments. Alternate distances or distance ranges may be used within the scope of this disclosure. In some embodiments, an antenna extender may correspond to certain category of extenders such as, for example, short, medium, and long. Differently sized antenna extenders may be used based placement of an implant within a patient, a patient&#39;s anatomy and/or the like. 
     In various embodiments, a reader device  508  may transmit energy to the implant  502  via the antenna extenders  506 . Similarly, the implant  502  may send data to the reader device  508  via the antenna extenders  506 . 
       FIG. 6A  illustrates a profile of an example cannulated instrument driver according to an embodiment. As illustrated by  FIG. 6A , a cannulated instrument driver  600  has a cannula  602  that extends from a first end  604  of the cannulated instrument driver toward a second end  606  of the cannulated instrument driver. 
       FIG. 6B  illustrates an example cannulated instrument driver holding a set screw  610  for implantation according to an embodiment. As illustrated by  FIG. 6B , an antenna extender  608  may be positioned within at least a portion of the cannula  602 . The remaining portion of the set screw  610  may be positioned at one end of the cannulated instrument driver  600  and outside of the cannula  602 . The cannula  602  may serve to protect an antenna extender  608  from damage during implantation. Once the set screw  610  is attached to an anchoring member, the cannulated instrument driver  600  may be retracted. Retraction of the cannulated instrument driver  600  may cause the antenna extender  608  to slide from the cannula  602 . 
     In various embodiments, an energy transfer system may utilize a relay device and one or more antenna extenders, as illustrated by  FIG. 7 . As shown in  FIG. 7 , a system  700  may include an implant  702 , one or more antennae  704 , one or more antenna extenders  706 , a relay device  708  and a reader device  710 . The energy transfer system as illustrated by  FIG. 7  may be utilized in connection with a relay device as described in connection with  FIG. 4A ,  FIG. 4B , or a different relay device. 
       FIGS. 1-7  illustrate a multi-axial tulip-head pedicle screw according to various embodiments. However, it is understood that other types of anchoring members may be used within the scope of this disclosure. For example, fixed head screws or screws having differently shaped heads may be used. As another example, a hook member, a cross-link connector, an offset connector, or a hybrid hook-screw member may be used as well. Alternatively, non-anchoring members, such as, for example, an implant rigidly connected to a single rod, may be used within the scope of this disclosure. 
     The features and functions described above, as well as alternatives, may be combined into many other different systems or applications. Various alternatives, modifications, variations or improvements may be made by those skilled in the art, each of which is also intended to be encompassed by the disclosed embodiments.