Patent Publication Number: US-9889304-B2

Title: Leadless neurostimulator

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit of priority under 35 U.S.C. § 120 as a continuation of U.S. patent application Ser. No. 15/194,033, filed Jun. 27, 2016 and issued as U.S. Pat. No. 9,572,985 on Feb. 21, 2017, which claims the benefit of priority under 35 U.S.C. § 121 as a divisional of U.S. patent application Ser. No. 14/470,356, filed on Aug. 27, 2014 and issued on Aug. 2, 2016 as U.S. Pat. No. 9,403,011. The contents of the foregoing applications are incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     Deep brain stimulation (DBS) is a neurostimulation therapy which involves electrical stimulation systems that stimulate the human brain and body. DBS can be used to treat a number of neurological disorders. Typically DBS involves electrically stimulating a target area of the brain. 
     SUMMARY 
     According to one aspect of the disclosure a neurostimulation device includes a stimulation capsule with a proximal and distal end. The stimulation capsule includes a MEMS film with a plurality of electrodes. The MEMS film defines a lumen. The stimulation capsule also includes a stimulation source disposed within the lumen and electrically coupled to at least one of the plurality of electrodes. The stimulation capsule can also include a power supply disposed within the lumen and electrically coupled with the stimulation source. The stimulation capsule can include a tether coupled with the proximal end of the stimulation capsule. 
     In some implementations, a diameter of the stimulation capsule is less than a diameter of the tether. The tether can include an antenna or the MEMS film can include a strip or a serpentine antenna. The antenna can be configured to operate at a center frequency of one of 6.790 MHz, 13.560 MHz, 27.120 MHz, 40.680 MHz, 433.920 MHz, 915.000 MHz, 2.450 GHz, 5.800 GHz, and 24.125 GHz. In some implementations, the antenna is forms a loop. The antenna can be used to program the stimulation capsule, and the antenna can include one or more wires in electrical communication with the stimulation capsule. The one or more wires can each couple with a wire tether contact disposed on a ribbon cable. The ribbon cable can extend from a distal end of the MEMS film into the lumen. 
     In some implementations, the stimulation source and the power supply are disposed on the ribbon cable. The power supply can be battery or super-capacitor. A recording circuit can also be coupled with the ribbon cable. In some implementations, the MEMS film includes a first polymeric layer, a first barrier layer, a metal layer, a second barrier layer, and a second polymeric layer. 
     According to another aspect of the disclosure, a method of manufacturing a stimulation device includes forming a MEMS film. The MEMS film can include a plurality of electrodes and a ribbon cable extending from a distal end of the MEMS film. The method can also include coupling a stimulation source with a first plurality of contacts. The first plurality of contacts can be disposed on a first face of the ribbon cable and can be in electrical communication with at least one of the plurality of electrodes. A power supply can be coupled with a second plurality of contacts. The second plurality of contacts can be disposed on a second face of the ribbon cable. The method also includes folding the ribbon cable toward a face of the MEMS film, and forming, with the MEMS film, a lumen. The ribbon cable can be disposed within the lumen. 
     In some implementations, the method also includes coupling a recording circuit on a third plurality of contacts disposed on the first face of the ribbon cable. The first face of the ribbon cable can be different than the second face of the ribbon cable. 
     The method can also include filling the lumen with an encapsulating epoxy. A lead wire can be coupled with a tether contact. The tether contact can be disposed toward a distal tip of the ribbon cable. In some implementations, the method includes heat molding the MEMS film to form the lumen. The power source can include a rechargeable battery of a super capacitor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The figures, described herein, are for illustration purposes only. Various aspects of the described implementations may be shown exaggerated or enlarged to facilitate an understanding of the described implementations. In the drawings, like reference characters generally refer to like features, functionally similar and/or structurally similar elements throughout the various drawings. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the teachings. The drawings are not intended to limit the scope of the present teachings. The systems and methods may be better understood from the following illustrative description with reference to the following drawings in which: 
         FIGS. 1A and 1B  illustrates an example leadless stimulator system. 
         FIGS. 2 and 3  illustrate an example leadless stimulator from the leadless stimulator system of  FIG. 1A . 
         FIG. 4  illustrates an enlarged view of the leadless stimulator from  FIGS. 2 and 3 . 
         FIGS. 5 and 6  illustrate an example MEMS film for use in the example leadless stimulator of  FIG. 1A . 
         FIG. 7  illustrates an enlarged view of example contact pads for the MEMS film of  FIGS. 5 and 6 . 
         FIGS. 8-13  illustrate an example, assembled contact pad for the MEMS film of  FIGS. 5 and 6 . 
         FIG. 14  illustrates an example leadless stimulator with a micro-antenna. 
         FIGS. 15-17  illustrate an example MEMS film for the example leadless stimulator of  FIG. 14 . 
         FIGS. 18 and 19  illustrate a cutaway view of an example leadless stimulator with micro-antenna. 
         FIGS. 20A and 20B  illustrate the internal arrangement of an example leadless stimulator. 
         FIGS. 21 and 22  illustrate another example MEMS film with a micro-antenna. 
         FIGS. 23A-23M  illustrate an example thin-film micro-fabrication method for fabricating a MEMS film. 
         FIG. 23N  illustrates an example method for forming the thin-film of  FIGS. 23A-23M  into a leadless stimulator. 
         FIG. 24  illustrates an example deployment system of the leadless stimulator system of  FIG. 1 . 
         FIGS. 25A and 25B  illustrate a cut away and perspective view, respectively, of the distal end of the guide tube for the deployment system of  FIG. 24 . 
         FIGS. 26A-26C  illustrate an example leg support stent for the deployment system of  FIG. 24 . 
         FIG. 27  illustrates an example MEMS film for the deployment system of  FIG. 24 . 
         FIGS. 28A and 28B  illustrate the MEMS film coupled with the leg support stent. 
         FIGS. 29A and 29B  illustrate an example outer tube of the guide tube. 
         FIGS. 30A and 30B  illustrate two views of the guide tube with the distal legs deployed. 
         FIGS. 31A and 31B  illustrate an example deployment mechanism for the deployment system of  FIG. 24 . 
         FIGS. 32A and 32B  illustrate the distal end of the example deployment system of  FIG. 24 . 
         FIGS. 33A and 33B  illustrate the distal end of the example deployment system of  FIG. 24 , with the distal legs deployed. 
         FIGS. 34A and 34B  illustrate the distal end of the example deployment system of  FIG. 24 , with the guide tube separated from the leadless stimulator. 
         FIGS. 35A-38B  illustrate an example method of implanting the leadless stimulator. 
         FIG. 39  illustrates a patient with a burr hole cover frame. 
         FIG. 40  illustrates a top view of the example burr hole cover frame after implantation into the craniotomy. 
         FIG. 41  illustrates a side view of the example burr hole cover frame after implantation into the craniotomy. 
         FIGS. 42A-42C  illustrate the example lower part of the burr hole cover frame from  FIG. 39 . 
         FIGS. 43A, 43B, and 43C  illustrate side, top, and perspective views of the burr hole cover cap. 
         FIGS. 44A and 44B  illustrate different views of the bottom-side of the burr hole cover cap from  FIGS. 43A-43C . 
         FIGS. 45-47  illustrate the wrapping of the antenna around the lower part of the burr hole cover frame from  FIG. 39 . 
         FIGS. 48A-48E  illustrates an example of the leadless stimulator implanted near a patient&#39;s spinal cord. 
         FIG. 49  illustrates an example distributed stimulator. 
         FIG. 50  illustrates the example distributed stimulator of  FIG. 49  implanted into a patient. 
     
    
    
     DETAILED DESCRIPTION 
     The various concepts introduced above and discussed in greater detail below may be implemented in any of numerous ways, as the described concepts are not limited to any particular manner of implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes. 
     The present disclosure describes a medical device to provide neurostimulation therapy to a patient&#39;s brain. The device can be surgically implanted and generally can remain in the patient until end of life. The present disclosure also describes accessories which guide the implantation of the device, and the components that form a leadless stimulator implantation kit. 
       FIG. 1A  illustrates an example leadless stimulator system  50 . The leadless stimulator system  50  can include a leadless stimulator  100 , a deployment system  305 , a burr hole cover frame  400 , and an external programmer  500 . The leadless stimulator  100  can include an antenna  200  and a stimulation capsule  120 . The stimulation capsule  120  is coupled with the antenna  200  by a tether  190 . The deployment system  305  can be used to implant the leadless stimulator  100  into a patient—for example, into a patient&#39;s brain through a craniotomy. The burr hole cover frame  400  can be used to secure the antenna  200  and the correctly position the antenna  200  for communication with the external programmer  500 . The external programmer  500  can read and write data to the leadless stimulator  100  through wireless communication with the leadless stimulator  100  using the antenna  200  of the leadless stimulator  100 . 
     As illustrated in  FIG. 1 , the leadless stimulator system  50  can include an external programmer  500 . The external programmer  500  can include a main unit  510 , which holds the power source and electronics for the operation of the external programmer  500 . The main unit  510  can include a screen  520  to provide visual information to the user. In some implementations, the screen  520  is a touch screen. The external programmer  500  can also include an antenna tether  530  that tethers the external programmer  500  to the external antenna  540 . In some implementations, the external antenna  540  can have a diameter that provides efficient communication with the leadless stimulator  100  via the antenna  200  of the leadless stimulator  100 . For example, the external antenna  540  could have a diameter between about 25 mm and about 75 mm or between about 45 mm and about 55 mm while the implanted antenna  200  can have a diameter between about 15 mm and about 35 mm or between about 20 mm and about 30 mm. The external programmer  500  can communicate with the leadless stimulator  100  wirelessly after the implantation of the leadless stimulator  100 . The external programmer  500  can send data to the leadless stimulator  100  in order to set the stimulation parameters of the leadless stimulator  100 . For example, the external programmer  500  can set signal attributes such as frequency, pulse width, amplitude, polarity, and signal shape, along with additional stimulation parameters, or a combination thereof. The final delivered pulses can be charge balanced, such that the pulse can have a cathodal and anodal phase. In some implementations, it is advantageous for the electrode if the amount of charge delivered during the cathodal phase is substantially equal to the amount of charge delivered during the anodal phase. Generally the pulses have a pulse width between 20 us and 1 ms, and the pulse frequency is between 20 Hz and 10 kHz depending on the clinical application. The external programmer  500  can also be used to turn the leadless stimulator  100  on or off. The external programmer  500  can also be used to control the post-operative neural recording features of the leadless stimulator  100 . The external programmer  500  can be used to download data (e.g., usage data and recorded physiological data) from the leadless stimulator  100 . In some implementations, the external programmer  500  can receive the data from the leadless stimulator  100  in substantially real time and in other implementations the leadless stimulator  100  may store the data for later retrieval with the external programmer  500 . 
     In some implementations, the external programmer  500  may be used to recharge the internal batteries of the leadless stimulator  100 . The external antenna  540  can be used to inductively couple power from an external power source to the leadless stimulator  100 . In other implementations, the leadless stimulator  100  can have no internal power source. In this case the inductively coupled power from external programmer  500  can be used to power the leadless stimulator  100 . In general, the leadless stimulator  100  can consume between about 5 mW and about 15 mW in clinical operation, and therefore the external programmer  500  is configured to supply sufficient power to charge the leadless stimulator  100  based on these demands. 
       FIG. 1B  illustrates the leadless stimulator  100  implanted into a patient&#39;s brain system  50  with the burr hole cover frame  400  and the external programmer  500  external to the patient&#39;s brain. The leadless stimulator  100  can be implanted responsive to the patient having a surgical planning procedure that involves MRI and/or CT scans to localize brain targets, thereafter the leadless neurostimulator  100  can be implanted in the deep brain using components of the leadless neurostimulator system  50 . The deployment system  305  can push the leadless neurostimulator  100  to the brain target, and subsequently removed leaving the leadless stimulator  100  towards the brain target. The implantable antenna  200  remains remain extra-cranial. The burr hole cover frame  400  is used to fill the burr hole and stabilize the leadless stimulator  100 . As described below, in some implementations, implantable antenna  200  is wrapped around the burr hole cover frame  400  to provide the correct diameter for efficient extra-corporeal communication. After implantation and surgical recovery, the external programmer  500  is used to program the leadless stimulator  100 . The external programmer  500  can also provide power, or in some implementations recharge, the leadless stimulator  100 . 
       FIGS. 2 and 3  illustrate the leadless stimulator  100 . In  FIG. 2  the antenna  200  is in a wrapped configuration, and in  FIG. 3  the antenna  200  is in an outstretched configuration. The leadless stimulator  100  can include a stimulation capsule  120 , a tether  190 , and an antenna  200 . The stimulation capsule  120  can include a plurality of electrodes and can record and/or stimulate the neurological tissue into which it is implanted. 
     The leadless stimulator  100  also includes an antenna  200  that can be coupled to the stimulation capsule  120  with the tether  190 . The tether  190  can provide a mechanical and electrical coupling between the antenna  200  and the stimulation capsule  120 . In some implementations, the antenna  200  is reversibly coupled with the tether  190  and in other implementations the antenna  200  is permanently coupled with the tether  190 . In some implementations, the tether  190  and the antenna  200  refer to the same part of the leadless stimulator  100 . For example, the part of the antenna outside of the patient may be referred to as the antenna  200  while the portion of the antenna inside the patient may be referred to as the tether  190 . As illustrated in  FIGS. 2 and 3 , part, or all, of the tether  190  and antenna  200  can be flexible. For example, the antenna  200  can be configured to be flexible enough to enable the antenna  200  to be coiled within a burr cover that is implanted in the patient&#39;s skull or to form a loop as illustrated in  FIG. 2 . The tether  190  and the antenna  200  have a diameter of about 0.5 mm, but could range from as small as 0.2 mm to as large as 2 mm. The wires that form the antenna  200  can form a bifurcated tail body. The bifurcated tail body forms an antenna loop. The antenna  200  can include a wire coil that is embedded in a flexible, elastomeric body. The antenna loop may be flexible enough be stretched over a burr hole cover, which can position the antenna  200  in a predetermined shape (e.g., a loop of a predetermined diameter). In other implementations, as illustrated if  FIG. 2 , the antenna  200  may be wound into a circular loop of the predetermined diameter. The below discussed burr hole cover frame may be used to ensure the antenna  200  maintains the predetermined diameter. 
     The predetermined diameter of the antenna can enable the efficient coupling of antenna  200  and the external antenna  540  of the external programmer  500 . In some implementations, the leadless stimulator  100  communicates wirelessly with the external programmer  500  over the 27 MHz frequency. Other frequencies which could be used are any of those determined by the International Telecommunication Union Radiocommunication Sector (ITU-R) in their reserved Industrial, Scientific, and Medical (ISM) Bands such as for example, but not limited to, 6.780 Mhz, 13.560 MHz, 40.680 MHz, 2.450 GHz, 5.80 GHz. The antenna diameter can be inversely proportional to the wavelength of the signal the antenna  200  transmits over. For example, with a 27 MHz frequency the loop diameter of the antenna  200  can be about 25 mm in diameter. In general, the loop diameter of the antenna is about half the wavelength of the frequency used to communicate with the antenna. 
       FIG. 4  illustrates an enlarged view of the distal end of the leadless stimulator  100  from  FIGS. 1-3 . The stimulation capsule  120  is coupled with the tether  190  at the proximal end  127  of the capsule body  125 . The capsule body  125  can be conical or cylindrical in shape. The proximal end  127  can mate with the distal end of a cannula (not illustrated) during the implantation procedure. In general, the capsule body  125  includes a polymeric material and houses the active electronic components of the leadless stimulator  100 . In some implementations, electronic components may also be housed in the tether  190  and antenna  200 . The stimulation capsule  120  can include a hemispherical distal tip  126 . The distal tip  126  can include electronic components. These electronic components are generally integrated circuits, resistors, capacitors, or a combination thereof. 
     The stimulation capsule  120  can be cylindrical and have a larger diameter than the tether  190 . In some implementations, the diameter of the stimulation capsule  120  is between about 0.3 mm and about 3 mm, between about 0.75 mm and about 2.5 mm, between about 1 mm and about 2 mm, or between about 1.2 mm and about 1.6 mm. 
     The stimulation capsule  120  can also include a MEMS film  150 . The MEMS film  150  can manufactured as a substantially planar film, which is coupled around the capsule body  125 . In some implementations, the MEMS film  150  is wrapped to form a cylindrical shape and then glued or co-molded into place. The MEMS film  150  can include one or more electrodes  160 . As illustrated in  FIG. 4 , the MEMS film  150  includes twelve electrodes (only eight of the electrodes  160  are visible in  FIG. 4 ). In some implementations, the electrodes  160  can be implemented in a noble metal, such as platinum. In other implementations, the electrodes  160  can be implemented in gold, titanium, iridium oxide, platinum grey, platinum black, and oxides of titanium. As illustrated the electrodes  160  substantially square with rounded corners. In some implementations, the electrodes  160  can be circular, rectangular, or any other shape. In some implementations, the electrodes  160  can be used for physiological recordings and simulations. 
       FIGS. 5 and 6  illustrate the MEMS film  150  in its substantially planar configuration. The MEMS film  150  includes twelve electrodes  160  disposed across the exterior portion  157  of the MEMS film  150 . In some implementations, the MEMS film  150  has about 4, 6, 8, 12, 16, 24, 36, 48, 64, or more electrodes  160 . The electrodes  160  can be arranged in specific patterns. For example,  FIGS. 5 and 6  illustrate an electrode arrangement that includes three columns and four rows of electrodes  160 . In other implementations, the electrodes  160  can be rectangular electrodes that span the width of the exterior portion  157  and form ring electrodes when the MEMS film  150  is rolled into its cylindrical shape. 
     The MEMS film  150  also includes a ribbon cable  165 . The lower portion of the ribbon cable  165  includes the contact pad  175 . The contact pad  175  includes a plurality of contacts  170 . Each of the contacts  170  can be coupled with one or more of the electrodes  160  through traces embedded within the MEMS film  150 . For example, the MEMS film  150  may include twelve electrodes  160  and twelve contacts  170 . In this example, each of the contacts  170  may be coupled with a different one of the twelve electrodes  160 . In some implementations, the contact pad  175  may include fewer contacts  170  than electrodes  160 . In this example, one or more electrodes  160  may be coupled with the same contact  170 , such that they may be stimulated (or recorded from) as a single unit. In some implementations, the contact pad  175  includes contacts  170  configured for different purposes. For example, the contact pad  175  illustrated in  FIGS. 5 and 6  includes a second type of contacts—the wire tether contacts  172 . The different types of contacts are generally referred to as contacts  170 . The wire tether contacts  172  are used to couple the MEMS film  150  to the wires of the tether  190  and antenna  200 . The contacts  170  may be coupled to an application-specific integrated circuit (ASIC) or other electronic component that is housed within the stimulation capsule  120 . 
       FIG. 7  illustrates an enlarged view of the contact pad  175  from  FIGS. 5 and 6 . In some implementations, a metal layer  174  is deposited on the contacts  170 . The metal layer  174  can include gold or other metal such as platinum, titanium, or copper. In some implementations, the addition of a metal layer  174  increases the ease of welding or attaching electronic components (e.g., antenna wires) to the contacts  170 . In some implementations, the metal layer  174  improves the contacts&#39;  170  ability to go undergo flip-chip bonding. The improvement in creating a contact with the contacts  170  may be caused by the metal layer  174  rising above the polyimide surface of the contact pad  175 , making it easier for electronic components to be coupled to the contacts  170 . 
       FIGS. 8-13  illustrate the assembly of an example contact pad  175 .  FIG. 8  illustrates an ASIC  180  prior to its coupling with the contact pad  175 . In some implementations, the internal electronics of the stimulation capsule  120  are coupled to the contact pad  175 . As illustrated, a single ASIC  180  is coupled with the contact pad  175 ; however, the electronic components of the leadless stimulator  100  can be divided among a plurality of ASICs  180 , batteries, passive electronic components (e.g., resistors and capacitors), or other electronic components. The ASIC  180  includes a plurality of contacts  170 , which are bound to the contacts  170  of the contact pad  175 . The contacts  170  of the ASIC  180  can have the same pitch (e.g., spacing) as the pitch of the contact pad  175 , such that the contacts  170  align and can be coupled together. In some implementations, the ASIC  180  is coupled with the contact pad  175  when the MEMS film  150  is a planar configuration—prior to the MEMS film  150  being formed into a cylindrical (or other) shape. For example, the ASIC  180  may be coupled with the contact pad  175  prior to the contact pad  175  being removed from the substrate on which it was fabricated. The ASIC  180  can be thinned to a thickness of about 50 μm, and generally has a thickness between about 20 and about 550 μm, prior to the ASIC  180  being coupled with the contact pad  175 .  FIG. 9  illustrates the contact pad  175  after the ASIC  180  is bound to the contact pad  175 . As illustrated, the contacts  170  of the ASIC  180  are aligned and coupled with the contacts  170  of the contact pad  175 . In some implementations, the ASIC  180  includes the stimulation source that is used to stimulate tissue via the electrodes  160 . The ASIC  180  can also include a recording circuit. In some implementations, the stimulation capsule includes a plurality of ASIC  180 . 
       FIG. 10  illustrates the lead wires  192  coupled with the contact pad  175 . One or more lead wires  192  can be coupled to the one or more wire tether contacts  172 . The lead wires  192  can be electrically coupled with the antenna  200  through the tether  190 . The lead wires  192  can include platinum-iridium wire, and have a thin electrically isolating coating. Incoming signals from the antenna  200  can be transmitted to the ASIC  180 . The ASIC  180  can process these signals and record and stimulate through the electrodes  160  as instructed by the signals. The ASIC  180  can also transmit captured neural signals to a computer or other external device through by a transmission the signals over the antenna  200 . 
     In some implementations, after the components of the leadless stimulator  100  are coupled together (while the MEMS film  150  is in a planar configuration) the MEMS film  150  can be molded into a cylindrical shape.  FIG. 11  illustrates the MEMS film  150  molded into a cylindrical shape. The shaping of the MEMS film  150  into a non-planar shape (e.g., a cylinder) can be performed by heat molding the MEMS film  150  while protecting the mounted ASIC  180  or by molding the ASIC  180  in place. As illustrated the contact pad  175 , with its coupled ASIC  180 , is toward the MEMS film  150 . The exterior portion  157  can then be rolled around the contact pad  175 , such that the contact pad  175  with its coupled ASIC  180  (e.g., the stimulation source, the power supply, and the recording circuit) is within a lumen created by the rolled exterior portion  157 . 
       FIG. 12  illustrates a cutaway view of the MEMS film  150  molded into a cylindrical shape.  FIG. 12  illustrates the folding of the MEMS film  150  into a cylindrical and the internal electronics of the MEMS film  150 . As illustrated the ribbon cable  165  can be folded back such that the contact pad  175  at least partially overlaps the exterior portion  157 . The edges of the exterior portion  157  are then rolled to create a cylinder around the ASIC  180 . Once the exterior portion  157  is rolled into a cylindrical form, the created cylinder can be co-molded to create the leadless stimulator  100 . 
       FIG. 13  illustrates an enlarged view of an example stimulation capsule  120 . The rolled MEMS film  150  can be over-molded to create a mechanically stable device. In some implementations, the MEMS film  150  is rolled to create the cylindrical shape. The capsule body  125  of the leadless stimulator  100  is then manufactured by co-molding the MEMS film  150  to encapsulate the interior of the MEMS film  150  and the electronics therein. The co-molding of the MEMS film  150  can involve securing the MEMS film  150  in place and having it back-filled with a polymer precursor, such as an epoxy, to backfill the cavities within the molded MEMS film  150 . The over-molding material may include epoxy materials, such as EPO-Tek 353, that provide sealing of the electronics and wire traces therein, protecting the electronics from body fluids that may disrupt electrical function. The stimulation capsule  120  can also include a distal tip  126 . The distal tip  126  can be coupled with the capsule body  125  or the distal tip  126  can be created as part of the capsule body  125  during the over-molding process. As illustrated the distal tip  126  is hemispherical, although other shapes may be used. For example, the distal tip  126  can be beveled or blunt. The distal tip  126  enables atraumatic insertion of the leadless stimulator  100  into tissue during the implantation procedure. 
       FIG. 13  also illustrates the tether  190 . The tether  190  can include a jacket, such as a polymeric tubing, around the lead wires  192 . In some implementations, the tether  190  can be hollow and have a lumen through which the lead wires  192  run. In other implementations, the tether  190  can be filled, encapsulating the lead wires  192  or other electronic components in the lumen of the tether  190 . In some implementations, the tether  190  is of a diameter of 0.5 mm, is flexible and easily wraps around a finger of a surgeon for example. 
     In some implementations, the leadless stimulator  100  may not include an antenna  200  at the surface of the skull. For example, the leadless stimulator  100  may include an integrated antenna (also referred to as a micro-antenna) on the stimulation capsule  120 . An integrated antenna can reduce the risk of malfunction due to broken lead wires. 
       FIG. 14  illustrates an example leadless stimulator  100  with a micro-antenna. The leadless stimulator  100  with a micro-antenna can include a stimulation capsule  120  and a tether  190 . In some implementations, for example with a micro-antenna, the tether  190  may not include lead wires to form an antenna; however, the leadless stimulator  100  may still include the tether  190  to facilitate the removal of the leadless stimulator  100  from a patient&#39;s tissue after implantation. 
       FIGS. 15 and 16  illustrate an example MEMS film  150  with a micro-antenna. The MEMS film  150  can include an exterior portion  157 , a ribbon cable  165 , and contacts  170 . The exterior portion  157  includes nine electrodes  160  and a micro-antenna  661 . In some implementations, the exterior portion  157  includes more than or fewer than nine electrodes  160 . As illustrated in  FIG. 15 , the contact pad  175  includes a battery pad  684 , on which a battery may be coupled. The battery may be coupled with the battery pad  684  in a means (e.g., flip chip bonding) similar to the means that an ASIC  180  is coupled to the contact pad  175 . After the electronic components are coupled with the MEMS film  150 , the battery pad  684  can be folded over on the contacts  170  of the contact pad  175 . In the example illustrated in  FIG. 15 , the ribbon cable  165  is divided into two separate ribbon cables. In some implementations, the metal layer of the MEMS film  150  that includes the traces from the electrodes  160  to the contacts  170  and the micro-antenna  661  is covered by a top insulating layer to electrically insulate the components. 
       FIG. 16  illustrates an enlarged view of the example MEMS film  150  from  FIG. 15 . In  FIG. 16  the top insulating layer of the MEMS film  150  is removed to illustrate the electrical elements embedded within the MEMS film  150 . For example, removal of the top insulating layer exposes the micro-antenna  661  and the electrical traces  658 . The electrical traces couple the electrodes  160  with the contacts  170  (or other electrodes  160 ). The micro-antenna  661  is embedded in the metal layer of the MEMS film  150 . The micro-antenna  661  is serpentine in shape and is designed in order to be highly efficient at the chosen transmission frequencies. 
       FIG. 17  illustrates a perspective view of an example leadless stimulator  100  with a micro-antenna  661 . The MEMS film  150  can be rolled into a cylindrical shape. The MEMS film  150  can then be over-molded to create a capsule body  125 . In some implementations with a micro-antenna  661 , the tether  190  does not include antenna wires, and the tether  190  is used for the extraction of the leadless stimulator  100  from a patient after implantation. In some implementations, the tether  190  is embedded within the distal tip  126 . Having the tether  190  run through the length of the body can reduce the chance of the tether  190  breaking free of the stimulation capsule  120 . 
       FIGS. 18 and 19  illustrate a cutaway view of an example leadless stimulator  100  with micro-antenna  661 . As discussed above in relation to  FIG. 17 , the tether  190  can be coupled to the distal tip  126 .  FIG. 18  illustrates that the tether  190  passes through the body of the stimulation capsule  120  and is coupled with the distal tip  126 . The ribbon cable  165  is divided into two parts (ribbon cable  165 A and ribbon cable  165 B) to facilitate the passage of the tether  190  through the capsule body  125 . As illustrated in  FIG. 19 , the tether  190  can pass between the two parts of the ribbon cable  165 .  FIGS. 18 and 19  also illustrate the placement of the power supply  181 . In some implementations, the power supply  181  is a battery. The power supply  181  may be recharged by the external programmer  500 . Generally, the power supply  181  can have enough charge to provide stimulation for at least one day, or about 200 mAh, and in some implementations up to several weeks, or around 2300 mAh. 
       FIGS. 20A and 20B  illustrate the internal arrangement of an example leadless stimulator  100  with a micro-antenna. The contacts  170  of the ASIC  180  can be aligned with and bonded to the respective contacts  170  of the contact pad  175 . The contacts  170  of the power supply  181  can be aligned with and bonded to the respective contacts  170  of the battery pad  684 . In some implementations, the ASIC  180  (or other components) can be wire bonded to the MEMS film  150  through wire bonds. Referring to  FIGS. 20A-20B , among others, the power supply  181  and the ASIC  180  are placed on opposite sides of the tether  190  as the tether  190  passes through the body of the stimulation capsule  120 . 
       FIGS. 21 and 22  illustrate an example MEMS film  150  with a micro-antenna  661 . As illustrated in  FIG. 21 , the MEMS film  150  includes a micro-antenna  661  on the distal portion of the contact pad  175 . The micro-antenna  661  is disposed on a projection  176  from the contact pad  175 . When forming the stimulation capsule  120 , the micro-antenna  661  can be rolled to form a loop, which is housed within the rolled MEMS film  150 .  FIG. 22  illustrates a cutaway view of the stimulation capsule  120  with the rolled micro-antenna  661  located in the internal portion created by the rolled MEMS film  150 . 
       FIGS. 23A-23M  illustrate a cross-sectional view of an example thin-film micro-fabrication method for fabricating the MEMS film  150 . The MEMS film  150  can be fabricated using a plurality of techniques and the below describe method illustrates one possible method for fabricating the MEMS film  150 . The fabrication procedure can include a series of procedural steps in which various layers are deposited or removed (e.g., etched) to achieve a final form. The cross sections in  FIG. 23A  through  FIG. 23M  demonstrate the process steps to build a MEMS film  150 . 
     In a first step illustrated in  FIG. 23A , a carrier substrate  2301  is provided, such as a wafer composed of a crystalline material, such as silicon, or an amorphous material, such as a thermal shock resistant borosilicate glass or other suitable smooth supportive material. A first layer  2302 , which can include one or more sub-layers, is applied to a surface of the wafer  2301 . One of the sub-layers can be a sacrificial layer deposited on the wafer  2301 , which is removed in a subsequent electrochemical etching step. In some implementations, the sacrificial sub-layer is preceded by another sub-layer, referred to as an underlayer, which can serve to form the electrochemical cell required to etch the sacrificial layer. The sacrificial sub-layer can be aluminum, or an alloy of aluminum such as AlSi, which has a smaller granularity, whereas the underlayer can be a TiW alloy such as Chrome or similar metal. 
     Referring to  FIG. 23B , the next step in the fabrication process can include depositing a first polymeric layer  2305 . The first polymeric layer  2305  can be deposited upon the sacrificial layer  2302  by MEMS processes such as, but not limited to, (i) spin coating a liquid polymer precursor such as Polyimide or Silicone precursor; (ii) depositing a polymer through chemical vapor deposition as is done with parylene-C; or (iii) laminating a polymer sheet onto the wafer. In some embodiments, the polymer layer  2305  is heated, or baked, to polymerize. In some implementations, the first polymeric layer  2305  includes polyamic-acid dissolved in NMP and spun onto the sacrificial layer  2302  in liquid form. The polymeric layer  2305  is heated into a imidized polyimide. The polymer in its cured form is between about 5 μm and about 15 μm thick. 
     Referring next to  FIG. 23C , the deposition of a barrier layer. The barrier layer can serve both as a layer to aid the adhesion and durability of subsequent layers. The barrier layer can also serve as an ionic barrier, and limit ions from reaching the metal layers, which could compromise electrical performance. The barrier layer can also block humidity from reaching the interlayers and the metal layer, which could create short circuits and compromise electrical isolation. 
     In some implementations, the barrier layer is deposited onto the first polymeric layer  2305  by vapor deposition techniques such as chemical vapor deposition (CV) and plasma enhanced chemical vapor deposition (PECVD), or by sputtering techniques such as direct current (DC) or RF (Radio Frequency) sputtering. The barrier layer can include Silicon Nitride, Silicon Oxide, Silicon Carbide, Poly-Silicon, or Amorphous-Silicon. In some implementations, the barrier layer can also include other non-conductive materials, such as Titanium Dioxide or Titanium (III) Oxide. The final thickness of the barrier layer can range from about 100 nm to about 2 μm. In some implementations, the barrier layer is about 400 nm to about 600 nm, which can permit the barrier layer to be flexible enough to bend during subsequent assembly techniques. 
     Now referring to  FIG. 23D , a metal layer  2315  can be deposited over the entire wafer on the surface of the barrier layer  2310 . Subsequently, a photoresist layer  2317  can be deposited. The photoresist layer  2317  can be defined by exposing areas of the photoresist layer  2317  to ultra-violet light and developing those areas in a solvent. Thus, the exposed areas of the photoresist layer  2317  will be selectively removed and areas of the metal layer  2315  will be exposed. The areas of the metal layer  2315  covered by the photoresist layer  2317  can form the electrodes, traces, and other components of the final product that are within the metal layer. 
     The metal layer  2315  can include a variety of metals such as titanium, platinum, gold, and others metals used in neuromodulation. To improve adhesion of a metal layer  2315 , the metal layer  2315  can be applied in layers. For example, the metal layer  2315  can be applied as a first layer, such as titanium, then a middle layer, such as platinum, and finally an upper layer, such as titanium. This tri-layer metal structure can improve adhesion below and above the platinum layer by using the titanium as an adhesion layer to the barrier layer. The typical thicknesses for the adhesion layer of titanium can be between about 20 nm and about 100 nm or between about 25 nm and about 75 nm. Typical thicknesses for the platinum layer can be between about 200 nm and about 400 nm or between about 250 nm and about 350 nm. 
       FIG. 23E  illustrates the process after the etching of the metal layer  2315 . As illustrated, the metal layer  2315  can be locally removed in the areas that were not covered by the photoresist  2317 . In some implementations, etching of the metal layer is performed in a plasma etcher such as a Reactive Ion Etcher. In some implementations, titanium and platinum can be etched with chlorine gas. After the etching process is finished, the photoresist layer  2317  can be removed using a solvent. 
     Another method to deposit and define the metal layer is using the so-called “lift off” technique. In this method the photoresist layer can be deposited onto the barrier layer  2310  first. The photoresist layer can be defined using photolithography. The metal layer  2315  can then be deposited through this “lift off” mask, and the remaining photoresist removed in a solvent. In this method the metal layer is transferred onto the barrier layer without the need of plasma etching and may have some process costs and speed advantages. 
     Referring next to  FIG. 23F , a deposition of a second barrier layer  2320  is performed. The second barrier layer can be deposited using the same techniques as the first barrier layer  2310 . The second barrier layer  2320  can be the same thickness, or a different thickness as the first barrier layer. In some implementations, the second barrier layer is optional. The second barrier layer  2320  and the first barrier layer  2310  can substantially surround the metal layer  2315 , rendering it electrically isolated. In order to etch and define the first and second barrier layer  2310  and  2320 , respectively, a second photoresist layer  2327  is deposited and photolithographically defined with clean room techniques. 
     The two barrier layers are etched, as illustrated in  FIG. 23G . The barrier layers can be etched using a plasma etch. An example of an etching process would be a reactive ion etching using a tetrafluoromethane gas, (CF4). The second photoresist layer  2327  can be removed using a solvent dissolution. 
       FIG. 23G  illustrates that the edges of the barrier layers  2310  and  2320  are defined, but the etch does not reach the metal layer  2315 . This is optional, and in some implementations the photolithography can include an opening above the metal layer  2315 , which would result in exposing the metal layer  2315 . 
       FIG. 23H  illustrates the application of a second polymer layer  2330 . The second polymer layer  2330  can be the same or a different polymer from the first polymer layer  2305 , and it can be the same or a different thickness. 
       FIG. 23I  illustrates the deposition of a third photoresist  2337 , which can form the etching perimeter of the first and second polyimide layers  2305  and  2330 , respectively. In some implementations, prior to the applying the third photoresist  2337 , a sacrificial layer, such as Silicon Dioxide or Silicon Nitride, is deposited in order to serve as an etch mask for the polyimide etch. For example, a silicon dioxide layer of thickness of about 500 nm can be deposited, which will serve as the etch mask for the process. 
       FIG. 23J  illustrates the result of an oxygen plasma etching of the first and second polyimide layers  2305  and  2330 , respectively. If applied, the silicon dioxide layer can be removed through an additional etch. 
       FIG. 23K  illustrates the deposition of a fourth photoresist layer  2347 . The fourth photoresist layer  2347  does not cover part of the metal layer  2315 . The opening  2332  maintained is designed to create a region for a gold layer to grow. 
       FIG. 23L  illustrates the galvanic growth of a thick gold layer  2350  into the opening  2332 . In some implementations, the gold layer  2350  is achieved by connecting the metal traces in the wafer to a perimetric metal band that allows an electrical connection between the edge of the wafer and the metal opening  2332 . When immersed in a galvanic bath and a current applied, the gold will grow on the metal layer  2315  using the metal layer  2315  as the seed layer for galvanic growth. In some implementations, the gold layer  2350  is about 2 μm to about 20 μm thick. The fourth photoresist layer  2347  can be removed using a solvent. 
       FIG. 23M  illustrates the removal of the MEMS film from the wafer  2301 . The removal of the fourth photoresist layer  2347  exposes the electrode opening  2333 . The MEMS film can be removed from the wafer  2301  by the removal of the sacrificial layer  2302  using electrochemically etching. Removal of the sacrificial layer  2301  frees the underside of the MEMS film from the wafer  2301 . In some implementations, the sacrificial layer  2301  is removed by placing the wafer in a saline bath with a high NaCl concentration. A platinum electrode also placed in the bath can be used as a reference, and a voltage can be applied to the aluminum layer with respect to the platinum electrode. The electrochemical cell created by the aluminum and TiW etches the aluminum—separating the MEMS film from the wafer  2301 . 
     When the MEMS wafer is completed, and the individual devices have been removed, they still require several process steps before being assembled into the cylindrical shape that is required. 
       FIG. 23N  illustrates a method  2360  for manufacturing a leadless stimulator. At step  2361 , a MEMS film is formed. The method for forming the MEMS film is described above in relation to  FIGS. 23A-23M . In general, the MEMS film is formed as a planar film. The MEMS film can include a plurality of electrodes and a ribbon cable that extends from the distal end of the MEMS film. 
     At step  2362 , a stimulation source is coupled with the MEMS film. Referring to  FIG. 8 , the stimulation source may be a component of an ASIC  180 . The stimulation source (or ASIC  180 ) can include a plurality of contacts  170 . The ribbon cable can also include a plurality of contacts  170 . As illustrated in  FIG. 8 , the contacts  170  of the ASIC  180  can be coupled with the contacts  170  of the ribbon cable. Coupling the contacts  170  of the ASIC  180  with the contacts  170  of the ribbon cable can enable an electrical connection between the ASIC  180  and one or more electrodes. 
     Referring again to  FIG. 23N , at step  2363 , a power supply is coupled with the MEMS film. As illustrated in  FIGS. 20A and 20B , a power supply  181  can be coupled with the MEMS film. The power supply can include a plurality of contacts, through which an electrical connection is established with the MEMS film. In some implementations, the power supply is coupled to the same face of the ribbon cable as the stimulation source, and in other implementations the power supply is coupled with a face opposite to the face the stimulation source is coupled. In some implementations, other circuitry such as recording circuitry, control circuitry, or other ASICs can be coupled with the ribbon cable. 
     At step  2364 , the ribbon cable is folded toward a face of the MEMS film. As illustrated in  FIG. 12 , the ribbon cable  165 , with the coupled stimulation source and power supply, are folded toward a face of the MEMS film. The MEMS film can include two primary faces. The first face includes the plurality of electrodes and the second face is the opposite face of the MEMS film. As illustrated in  FIG. 12 , the ribbon cable  165  is folded toward the second face of the MEMS film. 
     At step  2365 , the MEMS film is formed into a lumen. Also as illustrated in  FIG. 12 , the sides of the MEMS film are formed around the portion of the ribbon cable to which the stimulation source and power supply are coupled. The formed MEMS film defines a lumen, in which the stimulation source and power supply are disposed. The MEMS film can be heat formed such that the MEMS film maintains it shape after the forming process. In some implementations, the lumen defined by the formed MEMS film is filled with an encapsulating epoxy. The encapsulating epoxy can provide structural stability to the stimulation capsule and can also electrically isolate the electrical components disposed within the lumen. 
       FIG. 24  illustrates an example deployment system  305 . The deployment system  305  is used to implant the leadless stimulator  100 . The deployment system  305  includes a guide tube  300 . At the proximal end, deployment system  305  can include a connection plug  310 . The connection plug  310  enables electrical connections between the deployment system  305  and a controller or recording device used during the implantation of the leadless stimulator  100 . The connection plug  310  is coupled with the other components of the deployment system  305  via the connection cable  315 . The connection cable  315  can include electrical conductors, in the form of wires or traces, which electrically couple the distal electrodes  355  to the connection plug  310 . The deployment system  305  also includes a depth stop  320  to enable the surgeon to couple the deployment system  305  with stereotactic equipment. In some implementations, the depth stop  320  may also house pre-amplifier circuitry to improve the signals coming from the distal electrodes  355 . The depth stop  320  also includes a deployment handle  325 . The deployment handle  325  may be pushed up or down by the surgeon to deploy or retract, respectively, the distal legs  360 . In  FIG. 24 , the distal legs  360  are illustrated in the deployed state. The body of the deployment system  305  includes guide tube  300 . The guide tube  300  can include a leg support stent that is disposed around an inner cylinder. A MEMS film can be disposed around the leg support stent to form the distal legs  360 . 
       FIGS. 25A and 25B  illustrate a cut away and perspective view, respectively, of the distal end of the guide tube  300 . The inner cylinder  330  includes a central lumen  337 . The distal most end of the inner cylinder  330  includes a guide  339 . The guide  339  can mate with the proximal end of the stimulation capsule  120 . 
     In some implementations, the external diameter of the inner cylinder  330  is between about 0.5 mm and about 3 mm, between about 1 mm and about 2 mm, or about 1 mm and 1.5 mm. In some implementations, the internal diameter of the central lumen  337  is between about 0.25 mm and about 1.5 mm or between about 0.5 mm and about 1 mm. The internal diameter of the central lumen  337  can enable the insertion of the tether  190  and the antenna  200 . The guide  339  can have a slightly larger external diameter when compared to the inner cylinder  330 . For example, the diameter of the guide  339  may be about 1.5 mm when the outer diameter of the inner cylinder  330  is about 1 mm. The guide  339  can either be a separate piece, which is later coupled with the inner cylinder  330 , or the guide  339  can be machined from the same stock material as the inner cylinder  330 . The inner wall  340  of the guide  339  can surround the leadless stimulator  100 , and the outer wall  341  of the guide  339  can be used to guide the below described distal legs  360  during deployment. In some implementations, the inner cylinder  330  includes a metal, such as surgical stainless steel, and in other implementations, the inner cylinder  330  can include a polymer or other MRI compatible material such as a ceramic or titanium oxide. 
       FIGS. 26A-26C  illustrate an example leg support stent  344 . In some implementations, the external diameter of the leg support stent  344  is between about 0.5 mm and about 3 mm, between about 1 mm and about 2 mm, or about 1 mm and 1.85 mm. The internal diameter of the leg support stent  344  can be at least the external diameter of the inner cylinder  330 , such that the leg support stent  344  can be disposed around the inner cylinder  330 . The leg support stent  344  can include leg supports  342  at distal end of the leg support stent  344 . As illustrated, the leg support stent  344  includes four leg supports  342 . In some implementations, the leg supports  342  can be flexible enough to expand with the typical forces that can be applied by hand.  FIGS. 26B and 26C  illustrate the expanded leg supports  342 . In some implementations, the leg supports  342  of the leg support stent  344  slide distally along the inner cylinder  330 . When the leg supports  342  come into contact with the outer wall  341  of the guide  339 , the outer wall  341  can cause the leg supports  342  to expand. 
       FIG. 27  illustrates an example MEMS film  350  that can be coupled around the leg support stent  344 . The MEMS film  350  can include legs  352 . As illustrated the MEMS film  150  includes four legs  352 . In some implementations, the legs  352  are between about 5 mm and about 15 mm or between about 7 and about 12 mm in length. The legs  352  can be about 0.25 mm to about 1 mm in width. In some implementations, the legs  352  are about the same length and width as the leg supports  342 . One or more surfaces of the legs  352  can include a plurality of microelectrode elements  355 . As illustrated, each leg  352  includes five microelectrode elements  355 . In some implementations, different legs  352  can include a different number of microelectrode elements  355 . Each microelectrode elements  355  can include between 1 and about 10 microelectrode elements  355 . In some implementations, the legs  352  include more than 10 microelectrode elements  355 . The microelectrode elements  355  can be circular or rectangular in shape and have a diameter between about 100 μm and about 1000 μm, or between about 200 μm and about 700 μm, or between about 300 μm and about 500 μm. The MEMS film  350  can also include a shoulder  357  that can be coupled around the leg support stent  344 . The MEMS film  350  can further include a tether  359 , which carries traces from the microelectrode elements  355  to the proximal end of the guide tube  300 . In some implementations, there is one trace for each microelectrode elements  355  and in other implementations one or more microelectrode elements  355  may be coupled with the same trace. 
       FIG. 28A  illustrates the MEMS film  350  coupled with the leg support stent  344 . The MEMS film  350  can be coupled to the leg support stent  344  with glue or pressure bonding. The legs  352  are aligned and coupled with the leg supports  342 .  FIG. 28B  illustrates the MEMS film  150  coupled with the leg support stent  344 , with the leg supports  342  in the retracted state. 
       FIG. 29A  illustrates an example outer tube  370  of the guide tube  300 . The distal end of the outer tube  370  can include leg gaps  372 . The outer tube  370  can enable the leg supports  342  to fit within the leg gaps  372 . In some implementations, the outer tube  370  can have an outer diameter between about 0.5 and about 2.5 mm. In some implementations, the wall thickness of the outer tube  370  is about 0.2 mm. The outer tube  370  is generally implemented in a medical grade Stainless Steel such as 316, or could be implemented in a polymer such as polyimide to promote improved MRI Compatibility. 
       FIG. 29B  illustrates an example guide tube  300  with an outer tube  370  in place. The outer tube  370  can be placed concentrically over the MEMS film  350  and the leg support stent  344 . As illustrated in  FIG. 29B , the assembly guide tube  300  exposes the microelectrode elements  355  through the leg gaps  372  of the outer tube  370 . In some implementations, exposure of the microelectrode elements  355  through the leg gaps  372  enables the microelectrode elements  355  to record neural activity as the guide tube  300  descends into brain tissue. In some implementations, the guide tube  300  can perform neural recording to enable a surgeon to identify the guide tube&#39;s location with a patient&#39;s tissue. 
       FIGS. 30A and 30B  illustrate two views of the guide tube  300  with the distal legs  360  deployed. In some implementations, when reaching a target site within the tissue, the distal legs  360  can be deployed by a surgeon to perform neural recording. Each of the distal legs  360  can include a plurality of microelectrode elements  355 . In the illustrated example of  FIGS. 30A and 30B , each of the four distal legs  360  include five microelectrode elements  355 , for a total of twenty recording and stimulation sites. In some implementations, the guide tube  300  can include more or fewer distal legs  360 , each with more or fewer microelectrode elements  355 . 
       FIGS. 31A and 31B  illustrate an example deployment mechanism  319 . In some implementations, the deployment mechanism  319  can include a handle  325  that can be used to deploy the distal legs  360 , as illustrated in  FIGS. 30A and 30B . The leg support stent  344  can be attached to the deployment handle  325 . Accordingly, movement of the deployment handle  325  can be translated into movement of the leg support stent  344 , which results in the deployment or retraction of the distal legs  360 .  FIG. 31A  illustrates the position of the deployment handle  325  when the distal legs  360  are in the deployed state, and  FIG. 31B  illustrates the position of the deployment handle  325  when the distal legs  360  are in the retracted state. The central lumen  337  is visible on the proximal end of the deployment mechanism  319 . The deployment mechanism  319  can include depth stops  320  that can limit the movement of the deployment handle  325  in the proximal and distal directions. 
       FIGS. 32A and 32B  illustrate the distal end of the example deployment system  305  coupled with the leadless stimulator  100 . The deployment system  305  includes the guide tube  300  coupled with the leadless stimulator  100 . The stimulation capsule  120  is exposed at the distal end of the guide tube  300 . In some implementations, the proximal end  127  of the leadless stimulator  100  (hidden in  FIGS. 32A and 32B ) can couple with the guide  339  (hidden in  FIGS. 32A and 32B ) of the guide tube  300 . When the leadless stimulator  100  is coupled with the guide tube  300 , the guide tube  300  can be used to push the leadless stimulator  100  toward the target location in the tissue. 
       FIGS. 33A and 33B  illustrate the distal end of the example deployment system  305 , with the distal legs  360  deployed. In some implementations, when deployed, the distal legs  360  can enable the recording and stimulation of the region surrounding the stimulation capsule  120 . In some implementations, the intra-operative recording and stimulation procedure can be used to further determine the final position of the leadless stimulator  100 . In some implementations, the recording and stimulation procedure can be used to determine an improved stimulation and recording configuration for the leadless stimulator  100 . For example, the procedure may be used to determine if a subset of the electrodes  160  of the leadless stimulator  100  should be used for recording and stimulating. 
       FIGS. 34A and 34B  illustrate the distal end of the example deployment system  305 , with the guide tube  300  and stimulation capsule  120  separated—for example, after the surgeon has begun to retract the deployment system  305  from the patient&#39;s tissue. In some implementations, the distal legs  360  are retracted and then the deployment system  305  can be retracted from the tissue, leaving, as illustrated in  FIGS. 34A and 34B , the leadless stimulator  100  at the target location. 
       FIGS. 35-38  illustrate an example method of implanting the leadless stimulator  100 .  FIGS. 35A and 35B  illustrate the leadless stimulator  100  in the preimplantation position. The leadless stimulator  100  is positioned above a craniotomy  1055  in a patient&#39;s skull  1050 . The craniotomy exposes a portion of the brain  1060 . In some implementations, the leadless stimulator  100  and deployment system  305  are lowered into place from the exterior of the patient using stereotactic implantation tools (not illustrated). 
       FIGS. 36A and 36B  illustrate the positioning of the leadless stimulator  100  into the patient&#39;s brain  1060 . Using the stereotactic implantation tools, the surgeon drives the deployment system  305  into the patient&#39;s brain  1060 , which in turn pushes the leadless stimulator  100  into the position. In some implementations, the surgeon can record neural activity as with the deployment system  305  and leadless stimulator  100  as they are lowered toward the target location. 
       FIGS. 37A and 37B  illustrate the deployment of the distal legs  360  of the leadless stimulator  100 . In some implementations, the distal legs  360  are deployed to record neural activity when the leadless stimulator  100  is believed to be at the proper implantation location. The microelectrode elements  355  of the guide tube  300 , and optionally the electrodes  160  of the leadless stimulator  100  can be used to record the neural activity of the implanted location. This procedure may be referred to as “targeting.” Targeting procedure may include recording the electrical activity of the target anatomy using the microelectrode elements  355  and the electrodes  160 . A signal processing software can record and display the neural activity to the neurosurgical team. Responsive to the recorded neural activity, the team may determine if the leadless stimulator  100  is placed in the proper anatomical location. In some implementations, the microelectrode elements  355  and the electrodes  160  can be used to stimulate the anatomical target in order to evoke a physiological response in the patient—for example, eye twitching or parasthesia. This procedure of neurophysiological recording and evoked patient responses can lead the neurosurgical team to determine the best placement of the leadless stimulator  100 . 
       FIGS. 38A and 38B  illustrate the placement of the leadless stimulator  100  after the retraction of the deployment system  305 . Following the targeting procedure, the distal legs  360  can be retracted. The leadless stimulator  100  can be left in place and the deployment system  305  is retracted from the patient. As the deployment system  305  is retracted, the stimulation capsule  120  remains in place and is tethered with the antenna  200  by the tether  190 . The antenna  200  may exit the patient through the craniotomy  1055 . The surgeon may fill the craniotomy  1055  with surgical cement or bone paste, which can secure the antenna  200  in place. In some implementations, the antenna  200  is wound into a burr hole cover frame to secure and position the antenna  200 . 
       FIG. 39  illustrates a patient  1000  with a burr hole cover frame  400  in place.  FIG. 40  illustrates a closer view of the example burr hole cover frame  400 . The burr hole cover frame  400  can include a burr hole cover cap  450  that protects the antenna  200  and area of the skull where the craniotomy was performed. The burr hole cover frame  400  can also include a lower part  410 . In some implementations, the burr hole cover cap  450  can be secured to the lower part  410  by the burr hole cover cap  450  clipping into the lower part  410 . In another implementation, as illustrated in  FIG. 40 , the burr hole cover cap  450  can be secured to the lower part  410  by screws  462  through screw holes  456 . 
       FIG. 41  illustrates a side view of the example burr hole cover frame  400  after implantation into the craniotomy  1055 . The burr hole cover frame  400  can include the burr hole cover cap  450  coupled with the lower part  410 . The lower part  410  can include a burr hole insert  412 , through which the leadless stimulator  100  exits the patient. The burr hole insert  412  can fill the hole in the skull left by the craniotomy. The antenna  200  can wrap around the circumference of the lower part  410  to ensure the antenna  200  maintains a predetermined loop diameter. In some implementations, the lower part  410  is secured to the patient by one or more screws  462  or glue. 
       FIGS. 42A-42C  illustrate the example lower part  410  of the burr hole cover frame  400 .  FIGS. 42A, 42B, and 42C  illustrate side, top, and perspective views of the lower part  410 , respectively. The lower part  410  can include a cartwheel frame  415 . The cartwheel frame  415  can include an antenna notch  417  around the perimeter of the cartwheel frame  415 . In some implementations, the antenna  200  is wound around the perimeter of the cartwheel frame  415  and lies within the antenna notch  417 . The antenna notch  417  of the cartwheel frame  415  can include a hole  418  from which the antenna  200  can exit the central lumen  411  of the lower part  410  to be wrapped around the perimeter of the cartwheel frame  415 . The lower part  410  can also include a burr hole insert  412  that is inserted into the craniotomy  1055  of the patient. The burr hole insert  412  is about 8 mm in diameter in some implementations, but can range from 3 mm to 15 mm in diameter. The burr hole insert  412  is about 4 mm deep, but can range from 1 mm to 8 mm deep in some implementations. 
       FIG. 42B  illustrates that the lower part  410  can include securing screw holes  425  on the inner perimeter of the cartwheel frame  415  and on the spokes  416  of the lower part  410 . The securing screw holes  425  can be used to secure the burr hole cover frame  400  to the patient&#39;s skull by screwing screws through the securing screw holes  425  and into the patient&#39;s skull. The lower part  410  can also include screw holes  426  to secure the lower part  410  to the burr hole cover cap  450 . In some implementations, the lower part  410  has a diameter  420  of about 25 mm. Generally, the diameter is equivalent to the most efficient antenna diameter for the chosen transmission frequency as described above. 
       FIGS. 43A, 43B, and 43C  illustrate side, top, and perspective views of the burr hole cover cap  450 , respectively. In some implementations, the burr hole cover cap  450  can protect the antenna  200  and the patient&#39;s brain after its exposure by the craniotomy. The burr hole cover cap  450  can include a smoothed edge  452 . The smoothed edge  452  can reduce tissue erosion once implanted. The burr hole cover cap  450  can also include three securing screw holes  456  that can align with screw holes  426 . 
       FIGS. 44A and 44B  illustrate different views of the bottom-side of the burr hole cover cap  450 . The burr hole cover cap  450  can include a plurality of alignment guides  458  that are used to align the burr hole cover cap  450  with the lower part  410  before the two components are secured together. The burr hole cover cap  450  can also include a central boss  460  that can be used in the alignment of the two components and to plug the central lumen  411 . 
       FIGS. 45-47  illustrate the wrapping of the antenna  200  around the lower part  410 .  FIG. 45  illustrates the lower part  410  and the leadless stimulator  100  after implantation. The leadless stimulator  100  is implanted into the patient&#39;s brain and the lower part  410  has been inserted into the craniotomy. The tether  190  is coupled with the stimulation capsule  120  and extends through the central lumen  411  and transitions into the antenna  200 . 
       FIG. 46  illustrates the insertion of antenna  200  into the hole  418 . The hole  418  begins in the central lumen  411  and traverses through one of the spokes of the lower part  410  to the antenna notch  417 . 
     As illustrated in  FIG. 47 , the antenna  200  can then be wrapped around the lower part  410  in the antenna notch  417 . Wrapping the antenna  200  around lower part  410  can ensure that the antenna  200  forms a loop of proper diameter to increase the effectiveness of the antenna  200 . In some implementations, the antenna  200  can be secured to the lower part  410  with a clip or with a bonding agent. In some implementations, the proximal end of the antenna  200  includes a loop, which can be stretched over the perimeter of the cartwheel frame  415  and into the antenna notch  417 . 
     Deep Brain Stimulation can relieve the symptoms of Movement Disorders. The systems and methods described herein provide a more efficient and simple device to deliver the required therapeutic stimulation and in some cases provide neural recording. In the case of Movement Disorders the systems and methods described herein can provide efficient stimulation of the sub-thalamic nucleus, the Globus Pallidus interna, the Globus Pallidus externus, the Zone Incerta, or the Ventral Intermediate Nucleus to relieve symptoms such as rigidity and tremor. In other therapeutic domains such as psychiatric diseases, the systems and devices described herein can be implanted in the Cingulate Gyrus 25, the Medial Forebrain Bundle, the Nucleus Accumbens, the Ventral Striatum to deliver electrical stimulation and relieve the symptoms of Depression, Anxiety, Phobias, Obsessive Compulsive Disorder, or Post Traumatic Stress Disorder. 
     In some implementations, the leadless stimulator  100  can be implanted into anatomy of the patient other than the brain. For example, the leadless stimulator  100  may be used for pain management, spasticity, movement disorders, and spinal cord injury. In some of these implementations, the leadless stimulator  100  can be implanted near the patient&#39;s spinal cord.  FIG. 48A  demonstrates a representative human anatomy of the spinal column  4800 . There are a series of vertebrae  4820  separated by intervertebral discs  4830 . The spinal cord  4840  is also represented in the spinal canal  4845 .  FIG. 48B  illustrates a magnified section of the anatomy  4800  demonstrating the same anatomical sections with greater detail. 
       FIG. 48C  illustrates a perspective view of the anatomy  4800  with four implanted stimulation capsules  120 . The implantable antennas  200  remain outside of the epidural space, while the distal ends have been implanted on the surface of the spinal cord.  FIG. 48D  demonstrates the same surgical position from a different viewpoint angle.  FIG. 48E  illustrates a side, cut-away view of the patient&#39;s spinal cord. The stimulation capsule  120  is implanted dorsal to the spinal cord  1140 , vertebrae  1120 , and the intervertebral discs  1130 . 
       FIG. 49  illustrates an example distributed stimulator  900 . In some implementations, a plurality of leadless stimulators  100  can be implanted into a patient, and in other implementations a distributed stimulator  900  can be implanted into the patient. The distributed stimulator  900  includes a plurality of stimulation capsules  120  (four as illustrated in  FIG. 49 ) that can act in unison or similar to a plurality of independently implanted stimulation capsules  120 . The stimulation capsules  120  are coupled to a central control device  995 , which can include central antenna for the plurality of stimulation capsules  120 . Each of the stimulation capsules  120  are coupled to the central control device  995  by a tether  190 . As illustrated, the stimulation capsule  120  includes a plurality of ring electrodes around the circumference of each stimulation capsule  120 . 
       FIG. 50  illustrates the example distributed stimulator  900  implanted into a patient. The distributed stimulator  900  is implanted into the lumbar region  1210  of the patient. The distributed stimulator  900  has been implanted in a region that permits the distributed distal capsules to cover a region which would be advantageous to the surgical procedure, for example, the placement of the stimulation capsules  120  near the patient&#39;s spinal column as illustrated in  FIG. 48E . 
     Various implementations of the microelectrode device have been described herein. These embodiments are giving by way of example and not to limit the scope of the present disclosure. The various features of the embodiments that have been described may be combined in various ways to produce numerous additional embodiments. Moreover, while various materials, dimensions, shapes, implantation locations, etc. have been described for use with disclosed embodiments, others besides those disclosed may be utilized without exceeding the scope of the disclosure. 
     Devices described herein as either acute or chronic may be used acutely or chronically. They may be implanted for such periods, such as during a surgery, and then removed. They may be implanted for extended periods, or indefinitely. Any devices described herein as being chronic may also be used acutely. 
     The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Modifications and variations can be made without departing from its spirit and scope of this disclosure. Functionally equivalent methods and apparatuses may exist within the scope of this disclosure. Such modifications and variations are intended to fall within the scope of the appended claims. The subject matter of the present disclosure includes the full scope of equivalents to which it is entitled. This disclosure is not limited to particular methods, reagents, compounds compositions or biological systems, which can vary. The terminology used herein is for the purpose of describing particular embodiments, and is not intended to be limiting. 
     With respect to the use of substantially any plural or singular terms herein, the plural can include the singular or the singular can include the plural as is appropriate to the context or application. 
     In general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). Claims directed toward the described subject matter may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, such recitation can mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). Any disjunctive word or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, can contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” includes the possibilities of “A” or “B” or “A and B.” 
     In addition, where features or aspects of the disclosure are described in terms of Markush groups, the disclosure is also described in terms of any individual member or subgroup of members of the Markush group. 
     Any ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. Language such as “up to,” “at least,” “greater than,” “less than,” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, a range includes each individual member. 
     One or more or any part thereof of the techniques described herein can be implemented in computer hardware or software, or a combination of both. The methods can be implemented in computer programs using standard programming techniques following the method and figures described herein. Program code is applied to input data to perform the functions described herein and generate output information. The output information is applied to one or more output devices such as a display monitor. Each program may be implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the programs can be implemented in assembly or machine language, if desired. In any case, the language can be a compiled or interpreted language. Moreover, the program can run on dedicated integrated circuits preprogrammed for that purpose. 
     Each such computer program can be stored on a storage medium or device (e.g., ROM or magnetic diskette) readable by a general or special purpose programmable computer, for configuring and operating the computer when the storage media or device is read by the computer to perform the procedures described herein. The computer program can also reside in cache or main memory during program execution. The analysis, preprocessing, and other methods described herein can also be implemented as a computer-readable storage medium, configured with a computer program, where the storage medium so configured causes a computer to operate in a specific and predefined manner to perform the functions described herein. In some embodiments, the computer readable media is tangible and substantially non-transitory in nature, e.g., such that the recorded information is recorded in a form other than solely as a propagating signal. 
     In some embodiments, a program product may include a signal bearing medium. The signal bearing medium may include one or more instructions that, when executed by, for example, a processor, may provide the functionality described above. In some implementations, signal bearing medium may encompass a computer-readable medium, such as, but not limited to, a hard disk drive, a Compact Disc (CD), a Digital Video Disk (DVD), a digital tape, memory, etc. In some implementations, the signal bearing medium may encompass a recordable medium, such as, but not limited to, memory, read/write (R/W) CDs, R/W DVDs, etc. In some implementations, signal bearing medium may encompass a communications medium such as, but not limited to, a digital or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link, etc.). Thus, for example, the program product may be conveyed by an RF signal bearing medium, where the signal bearing medium is conveyed by a wireless communications medium (e.g., a wireless communications medium conforming with the IEEE 802.11 standard). 
     Any of the signals and signal processing techniques may be digital or analog in nature, or combinations thereof. 
     While certain embodiments of this disclosure have been particularly shown and described with references to preferred embodiments thereof, various changes in form and details may be made therein without departing from the scope of the disclosure.