AU2012244268A1 - External controller for an implantable medical device system with coupleable external charging coil assembly - Google Patents

Abstract

An improved integrated external controller/charger system useable with an implantable medical device is disclosed. The 5 system comprises two main components: an external controller and an external charging coil assembly that is coupleable thereto. When the external charging coil assembly is coupled to the external controller, the system can be used to both send and receive data telemetry to and from the implantable medical 10 device, and to send power to the device. Specifically, the external controller controls data telemetry by energizing at least one coil within the external controller, and the external controller controls power transmission by energizing a charging coil in the external charging coil assembly, which is otherwise 15 devoid of its own control, power, and user interface. The result is a cheaper, simpler, more compact, and more convenient data telemetry and charging solution for the patient having a medical implant. 2245115_1 (GHMatters) 30/10/12 CN C) (0N C*4 N Lc) C(4 CY) (N C 0-co (NN N N(

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicants: Boston Scientific Neuromodulation Corporation Invention Title: External controller for an implantable medical device system with coupleable external charging coil assembly The following statement is a full description of this invention, including the best method for performing it known to me/us: - 2 EXTERNAL CONTROLLER FOR AN IMPLANTABLE MEDICAL DEVICE SYSTEM WITH COUPLEABLE EXTERNAL CHARGING COIL ASSEMBLY RELATED APPLICATION 5 This application is a divisional application of Australian application no. 2008325058, the disclosure of which is incorporated herein by reference. 10 FIELD OF THE INVENTION The present invention relates to a data telemetry and/or power transfer technique having particular applicability to implantable medical device systems. 15 BACKGROUND Implantable stimulation devices are devices that generate and deliver electrical stimuli to body nerves and tissues for the therapy of various biological disorders, such as pacemakers to treat cardiac arrhythmia, defibrillators to treat cardiac 20 fibrillation, cochlear stimulators to treat deafness, retinal stimulators to treat blindness, muscle stimulators to produce coordinated limb movement, spinal cord stimulators to treat chronic pain, cortical and deep brain stimulators to treat motor and psychological disorders, and other neural stimulators 25 to treat urinary incontinence, sleep apnea, shoulder sublaxation, etc. The present invention may find applicability in all such applications, although the description that follows will generally focus on the use of the invention within a Spinal Cord Stimulation (SCS) system, such as that disclosed in 30 U.S. Patent 6,516,227, which is incorporated herein by reference in its entirety. Spinal cord stimulation is a well-accepted clinical method for reducing pain in certain populations of patients. As shown 35 in Figures 1A and 1B, a SCS system typically includes an 2245115_1 (GHMatters) 30/10/12 - 3 Implantable Pulse Generator (IPG) 100, which includes a biocompatible case 30 formed of titanium for example. The case 30 typically holds the circuitry and power source or battery necessary for the IPG to function, although IPGs can also be 5 powered via external RF energy and without a battery. The IPG 100 is coupled to electrodes 106 via one or more electrode leads (two such leads 102 and 104 are shown), such that the electrodes 106 form an electrode array 110. The electrodes 106 are carried on a flexible body 108, which also houses the 10 individual signal wires 112 and 114 coupled to each electrode. In the illustrated embodiment, there are eight electrodes on lead 102, labeled Ei-E, and eight electrodes on lead 104, labeled E,-E,,, although the number of leads and electrodes is application specific and therefore can vary. 15 Portions of an IPG system are shown in Figure 2 in cross section, and include the IPG 100, an external controller 12, and an external charger 50. The IPG 100 typically includes an electronic substrate assembly 14 including a printed circuit 20 board (PCB) 16, along with various electronic components 20, such as microprocessors, integrated circuits, and capacitors mounted to the PCB 16. Two coils are generally present in the IPG 100: a telemetry coil 13 used to transmit/receive data to/from the external controller 12; and a charging coil 18 for 25 charging or recharging the IPG's power source or battery 26 using the external charger 50. The telemetry coil 13 can be mounted within the header connector 36 as shown. As just noted, an external controller 12, such as a hand 30 held programmer or a clinician's programmer, is used to wirelessly send data to and receive data from the IPG 100. For example, the external controller 12 can send programming data to the IPG 100 to set the therapy the IPG 100 will provide to the patient. Also, the external controller 12 can act as a 2245115_1 (GHMatters) 30/10/12 - 4 receiver of data from the IPG 100, such as various data reporting on the IPG's status. The communication of data to and from the external 5 controller 12 occurs via magnetic inductive coupling. When data is to be sent from the external controller 12 to the IPG 100, coil 17 is energized with an alternating current (AC). Such energizing of the coil 17 to transfer data can occur using a Frequency Shift Keying (FSK) protocol for example, such as 10 disclosed in U.S. Patent Application Serial No. 11/780,369, filed July 19, 2007, which is incorporated herein by reference in its entirety. Energizing the coil 17 induces an electromagnetic field, which in turn induces a current in the IPG's telemetry coil 13, which current can then be demodulated 15 to recover the original data. The external charger 50, also typically a hand-held device, is used to wirelessly convey power to the IPG 100 again by magnetic inductive coupling, which power can be used to 20 recharge the IPG's battery 26. The transfer of power from the external charger 50 is enabled by a coil 17'. When power is to be transmitted from the external charger 50 to the IPG 100, coil 17' is likewise energized with an alternating current. The induced current in the charging coil 18 in the IPG 100 can 25 then be rectified to a DC value, and provided to the battery 26 to recharge the battery. As is well known, inductive transmission of data or power occurs transcutaneously, i.e., through the patient's tissue 25, 30 making it particular useful in a medical implantable device system. The inventors consider it unfortunate that the typical implantable medical device system 5 requires two external 2245115_1 (CHMatters) 30/10/12 - 5 devices: the external controller 12 and the external charger 50. Both are needed by a typical patient at one time or another with good frequency. The external charger 50 is typically needed to recharge the battery 26 in the lPG 100 on a 5 regular basis, as often as every day depending on the stimulation settings. The external controller 12 can also be needed on a daily basis by the patient to adjust the stimulation therapy as needed at a particular time. Therefore, the patient is encumbered by the need to manipulate two 10 completely independent devices. This means the patient must: learn how to use both devices; carry the bulk of both devices (e.g., when traveling); replace the batteries in both devices and/or recharge them as necessary; pay for both devices, etc. In all, the requirement of two independent external devices is 15 considered inconvenient. SUMMARY OF THE INVENTION According to one aspect of the invention there is provided a system for communicating with an implantable medical device, 20 comprising: an external controller integrated within a single housing, the external controller comprising at least one telemetry antenna within the housing for communicating data with the implantable medical device; and 25 an external charging coil assembly containing a charging coil for providing power to the implantable medical device, wherein the assembly is attachable to and detachable from the external controller at a port on the external controller. 30 According to a further aspect of the invention there is provided a system for communicating with an implantable medical device, comprising: an external controller integrated within a single housing comprising a user interface, a battery, and at least one 35 telemetry antenna within the housing for communicating data with the implantable medical device; and an external charging coil assembly containing a charging 2245115_1 (GHMatters) 30/10/12 -6 coil for providing power to the implantable medical device, wherein the assembly is coupleable to and controllable by the external controller via a cable, wherein the external charging coil assembly does not 5 contain a user interface or a battery. According to a further aspect of the invention there is provided a system for communicating with an implantable medical device, comprising: 10 an external controller for communicating data with the implantable medical device, wherein the external controller comprises a single port for interfacing with a source of data for the external controller, a source of power for the external controller, and an external charging coil assembly; and 15 an external charging coil assembly containing a charging coil for providing power to the implantable medical device, wherein the assembly is coupleable to the external controller at the port. 20 According to a further aspect of the invention there is provided a system for communicating with an implantable medical device, comprising: an external controller integrated within a single housing comprising a user interface, a battery, and at least one 25 telemetry antenna within the housing for communicating data with the implantable medical device, wherein the external controller comprises a single USB port for interfacing with an external charging coil assembly; and an external charging coil assembly containing a charging 30 coil for providing power to the implantable medical device, wherein the assembly is attachable to and detachable from the external controller at the USB port, wherein the external controller controls the charging coil. 35 2245115_1 (GHMatters) 30/10/12 -7 BRIEF DESCRIPTION OF THE DRAWINGS Figures 1A and 1B show an implantable pulse generator (IPG), and the manner in which an electrode array is coupled to the IPG in accordance with the prior art. 5 Figure 2 shows wireless communication of data between an external controller and an IPG, and wireless transfer of power from an external charger to the IPG. 10 Figure 3 shows an external controller/charger system in accordance with an embodiment of the invention comprising an external controller with a detachable external charging coil assembly. 15 Figure 4 shows the internal components of the external controller of Figure 3. Figure 5 shows another embodiment of an external controller/charger system in which the external controller 20 comprises a single power, data, and external charging coil assembly port. DETAILED DESCRIPTION The description that follows relates to use of the 25 invention within a spinal cord stimulation (SCS) system. However, the invention is not so limited. Rather, the invention may be used with any type of implantable medical device system that could benefit from improved coupling between an external device and the implanted device. For example, the 30 present invention may be used as part of a system employing an implantable sensor, an implantable pump, a pacemaker, a defibrillator, a cochlear stimulator, a retinal stimulator, a stimulator configured to produce coordinated limb movement, a 2245115_1 (GHMatters) 30/10/12 - 8 cortical and deep brain stimulator, or in any other neural stimulator configured to treat any of a variety of conditions. One embodiment of an improved external controller/charger 5 system 200 is illustrated in Figure 3. In system 200, data telemetry and charging functionality are integrated. The system 200 comprises two main components: an external controller 210 and an external charging coil assembly 220 that is coupleable thereto. When the external charging coil 10 assembly 220 is coupled to the external controller 210 as discussed further below, the system 200 can be used to both send and receive data telemetry to and from the IPG 100, and to send power to the IPG 100. As will be discussed further below, the external controller 210 controls data telemetry by 15 energizing at least one coil 62a or 62b (Fig. 4) within the external controller 210, and the external controller 210 controls power transmission by energizing a charging coil 250 in the external charging coil assembly 220, which is otherwise devoid of its own control, power, and user interface. 20 Allowing the external charging coil assembly 220 to be attached to and detached from the external controller 210 achieves good integration of the charging and data telemetry functions in an implantable medical device system, and 25 comprises a solution that mitigates many of the problems discussed in the Background. First, because the external charging coil assembly 220 does not contain a substantial amount of electronics, such as its own display, battery, microcontroller, etc., it is less bulky and easier to carry in 30 conjunction with the external controller 210. Moreover, the external charging coil assembly 220 lacks its own user interface, which instead is integrated as part of the user interface of the external controller 210. This makes the system 200 easier to use, as the patient does not need to learn 2245115_1 (GHMatters) 30/10/12 - 9 how to use or manipulate two completely independent devices. Because the external controller 210 powers both itself and the external charging coil assembly 220, there is only one battery to replace and/or recharge. The result is a cheaper, simpler, 5 more compact, and more convenient data telemetry and charging solution for the patient having a medical implant. Housing 215 of the controller 210 contains an additional port 225 into which a connector 230 on the charging coil 10 assembly 220 can be placed. The connector 230 is connected by a cable 235 to a charging coil housing 240 portion of the assembly 220. The charging coil housing 240 contains the charging coil 250, while the external controller housing 215 contains the data telemetry coils 62a and 62b, which are 15 disclosed in Figure 4 and will be discussed later. In the depicted embodiment, the charging coil housing 240 is roughly donut shaped to accommodate the circular shape of the charging coil 250, but the shape can vary. For example, the charging coil housing 240 can be disc shaped and thus can lack a central 20 hole. The charging coil 250 is preferably comprised of Litz wire, such as 25/38 Litz wire (in which each wire contains 25 individually-insulated strands of 38 gauge wire) or 50/41 Litz 25 wire (50 individually-insulated strands of 41 gauge wire). In a preferred implementation, the charging coil 250 exhibits an inductance of approximately 400 microhenries, which can be achieved by using approximately 75 turns of 25/38 Litz wire wound with a coil diameter (CD) of 5.5cm. However, these 30 values for the charging coil 250 are a matter of personal choice for the designer, and can be varied depending on the circumstances. For example, the coil diameter (CD) is preferably made large to maximize the reliability of coupling with the corresponding charging coil 18 in the IPG (see Fig. 2245115_1 (GiMatters) 30/10/12 - 10 2) . However, a larger coil diameter will require more power, which will increase the draw from the battery 126 in the external controller 210. (The controller 210's battery 126 will be discussed in further detail below). 5 The external charging coil assembly 220 can be assembled in many different ways, and one method for forming a flexible assembly is explained in detail here. As best seen in cross section in Figure 3, assembly can begin with a substrate 255 10 for holding the electronic components, such as the charging coil 250 and temperature-sensing thermistors 260, discussed further below. The substrate 255, if used, is preferably flexible and comprises any type of flexible substrates used to carry electronic circuitry, such as Kapton or Polyimide. The 15 charging coil 250 is wound to the specified number of turns, and is wound concurrently with the deposition of a silicone, such that the resulting coil 250 comprises wire windings in a flexible, insulative matrix of silicone. 20 Thereafter, thermistors 260 are placed on the substrate and attached to appropriate lead wires 265 leading towards the cable 235. As will be discussed further below, the thermistors 260 are designed to sense the temperature of the charging coil housing 240 during charging, i.e., when the charging coil 250 25 is energized, to ensure that a safe temperatures are maintained. For example, because the charging coil housing 240 may come into contact with a patient's skin, the thermistors 260 can report the temperature back to the external controller 210, which in turn can temporarily disable further charging if 30 the temperature is excessive (e.g., over 41 C or approximately 106 F). Thermistors 260 however are not strictly mandatory, and further can vary in number. For example, as shown in Figure 3, thermistors 260 can appear on the top or bottom of the substrate 255 (as shown in the cross section) or on 2245115_1 (GHMatters) 30/10/12 - 11 opposing sides of the housing 240 (as shown in the planar view) . If the housing 240 is disk shaped, the substrate 255 can likewise be disc shaped, and the thermistors 260 could in that arrangement be alternatively or additionally located in 5 the middle of the housing. Once the electrical components are mounted to the substrate 255, the lead wires are connected to wires in the cable 235. Then, the charge coil housing 240 is mold injected 10 around the resulting substrate 255. Silicone is preferred as the fill material for the mold injection process, because it yields a charge coil housing 240 that is soft and flexible. The result is a charge coil housing 240 that is comfortable and can conform to the patient's body. This is especially 15 important in an application where the patient must sit or otherwise place weight on the housing 240 to place it in a proper alignment with the IPG 100 while charging. The particular size of the charge coil housing 240 is not particularly important, but in one embodiment can comprise an 20 inner diameter (ID) of 4.0 cm, an outer diameter (OD) of 7.0cm, and a thickness (t) of 3.0mm. While the substrate 255 can be useful to stabilize the charging coil 250 and any associated electronics (e.g., 25 temperature sensors 260) prior to mold injection of the silicone, a substrate 255 is not strictly required. Mold injection of the housing 240 to encapsulate these components can occur even without the benefit of a substrate 255. 30 The external controller 210 controller and integrates data telemetry and charging functionality via its microcontroller and software (not shown), and provides the user access to such functionality through a user interface. The user interface generally allows the user to telemeter data (such as a new 2245115_1 (GHMatters) 30/10/12 - 12 therapy program) from the external controller 210 to the IPG 100, to charge the battery 26 in the IPG, or to monitor various forms of status feedback from the IPG. The user interface is somewhat similar to a cell phone or to other external 5 controllers used in the art, in that it includes a display 265, an enter or select button 270, and menu navigation buttons 272. Soft keys 278 can be used to select various functions, which functions will vary depending on the status of the menu options available at any given time. A speaker is also included within 10 the housing 215 to provide audio cues to the user (not shown). Alternative, a vibration motor can provide feedback for users with hearing impairments. It is generally preferred that the keys and buttons in the 15 user interface become automatically locked after some time period of non use (such as one minute) . This allows the user to then put the external controller 210 in his pocket for example without fear that any keys or buttons will become accidentally depressed. Unlock button 281, recessed into the 20 side of the housing, can be used to unlock the keys and buttons, and can be activated by pressing and holding that button for some duration of time (e.g., one second). The display 265 optimally displays both text and graphics 25 to convey necessary information to the patient such as menu options, stimulation settings, IPG battery status, external controller battery status, or to indicate if stimulation is on or off, or to indicate the status of charging. 30 The display 265 may comprise a monochrome liquid crystal display (LCD) using twisted nematic (TN) or super twisted nematic (STN) liquid crystal technology. The advantages of monochrome TN or STN LCDs are low cost, low power, and ease of programming. However, such benefits can be accompanied by 2245115_1 (GHMatters) 30/10/12 - 13 disadvantages, such as a relatively low resolution, narrow viewing angle (typically only 60 degrees), low contrast, low brightness, and slow response times. Brightness and contrast can be improved with a backlight, but this may increase cost, 5 power consumption, complexity, and electromagnetic interference (EMI) , especially in displays 265 with electroluminescent (EL) backlights, which require special high frequency and high voltage drive circuitry. LED backlights require lower voltages and are well-suited for minimizing electrical noise. 10 The display 265 may also comprise a color display such as a color super twisted nematic (CSTN) or thin-film transistor (TFT) LCDs. Compared to monochrome TN or STN LCDs, color CSTN and TFT LCDs provide higher resolution, wider viewing angles, 15 higher contrast, higher brightness, and faster response times. CSTN and TFT LCDs can range from 8-bit color displays (256 colors) to as high as 32-bit color displays (4.29 billion colors) . Color LCDs are typically backlit with white light emitting diodes (LEDs) which are low cost, low in EMI, more 20 reliable, and simpler to implement than traditional EL backlights. CSTN and TFT LCDs can also be made such that a backlight is not needed if ambient light is sufficient. This type of transreflective LCD can be visible even in direct sunlight. 25 The display 265 may further comprise an organic light emitting diode (OLED) display. OLED displays are available in monochrome, grayscale (typically 4-bit) , color (usually two or three colors), or full-color (8-bit to 32-bit color) . OLED 30 displays inherently have higher contrast (typically 5000:1) and wider viewing angles (nearly 180 degrees) when compared with color LCDs. OLEDs differ from color LCDs in that OLEDs are emissive (light-emitting) instead of transmissive (light filtering). In this regard, OLEDs emit light when a voltage is 2245115_1 (GHMatters) 30/10/12 - 14 applied across an active material (e.g., an organic polymer), whereas LCDs require color filters and a white backlight to produce color. Because a separate backlight is not needed, OLED displays can be made significantly thinner than color 5 LCDs, which in turn means that the external controller 210 can be made smaller. In addition, a typical image displayed on an OLED display requires less power than a comparable image on a color LCD. OLED displays are also potentially lower in cost than LCDs because, as mentioned, a backlight is not necessary, 10 which can be a significant portion of the display's cost. The internal structure of the external controller 210, with its housing 215 removed, is shown in Figure 4. As shown, a printed circuit board (PCB) 120 is central to the internal 15 construction of the controller 210. The front side of the PCB 120 carries aspects of the user interface, including the display 265 and pressure-sensitive switches 122 for receiving presses to the various user interface buttons 270, 272, 274, and 276 (Fig. 3) . In the depicted embodiment, the telemetry 20 coils 62a and 62b and the battery 126, are located on the back side of the PCB 120, along with other integrated and discrete components necessary to implement the functionality of the external controller, such as the microcontroller and firmware holding the operation system software. The external controller 25 210 would also contain the stimulation circuitry for energizing the charging coil 250, which circuitry would be similar to that traditionally found in a discrete external charger 50 (Fig. 2). Power to operate the external controller 210, including 30 the power needed to energize the telemetry coils 62a and 62b and the external charging coil 250 comes from a battery 126. The battery 126 can comprise standard disposable alkaline batteries (e.g., two to four AA or AAA batteries). However, in a preferred embodiment, the battery 126 is rechargeable, which 2245115_1 (GHMatters) 30/10/12 - 15 reduces battery costs and waste. In particular, a Lithium (Li) -ion battery or a Li-ion polymer battery is preferred for the battery 126. Such batteries have high cell voltages (e.g., 4.2V), such that one cell can replace numerous alkaline cells 5 in series. Such batteries also have high energy capacity, which can be nearly twice that of alkaline cells. A rechargeable Li-ion or Li-ion polymer battery 126 thus either allows for twice the runtime of alkaline cells in the same form factor, or the same runtime with about half the package size, 10 which enables a smaller external controller 210 design. Use of higher capacity of Li-ion or Li-ion polymer batteries for the battery 126 also promotes the use of higher current drain components in the external controller 210 such as 15 the color LCD or OLED displays 265 discussed earlier, which improve patient experience by offering a more legible display. In addition, due to the lower internal series resistance of Li ion or Li-ion polymer batteries, significantly higher current drains can be achieved, which improves functions requiring high 20 amounts of current, such as energizing the telemetry coils 62a/62b or the charging coil 250 in the external charging coil assembly 220. When higher currents are used to energize the coils, the communication range is increased. Furthermore, Li ion and Li-ion polymer batteries should typically remain 25 reliable for the life of the external controller 210, which means the battery 126 can be sealed in the housing 215 of the external controller 210. In other words, no opening needs to be made on the housing to allow a user to remove the battery 126, which improves reliability, safety, and lowers 30 manufacturing costs. Having said this, a latched battery opening can also be provided in the housing 215 of the external controller 210 even when a rechargeable battery 126 is used to allow for battery servicing if needed. 2245115_1 (GHMatters) 30/10/12 - 16 The battery 126 can be recharged much like a cellular telephone, and so can essentially be plugged into a 120V AC wall outlet. A power port 280 (Fig. 3) can receive power using an AC power source 292 (e.g., a wall plug), which is rectified 5 to DC levels by an AC-DC adapter 291. Alternatively, the housing 215 of the external controller 210 can carry two electrodes to allow the battery 126 to be charged while sitting in a charging cradle or docking station (not shown). 10 In a preferred implementation, and as seen in the back and side views of Figure 4, the two telemetry coils 62a and 62b are respectively wrapped around axes 54a and 54b which are orthogonal. More specifically, coil 62a is wrapped in a racetrack configuration around the back of the PCB 120, while 15 coil 62b is wrapped around a ferrite core 128 and affixed to the PCB 120 by epoxy. Further discussion of the benefits of orthogonally-oriented telemetry coils 62a and 62b can be found in U.S. Patent Application Serial No. 11/853,624, filed September 11, 2007, which is incorporated by reference in its 20 entirety. Briefly, when used to transmit data, the two coils 62a, 62b are driven (for example, with FSK-modulated data) out of phase, preferably at 90 degrees out of phase. This produces a magnetic field which rotates, and which reduces nulls in the coupling between the external controller 210 and the telemetry 25 coil 13 in the IPG 100. Should dual coils 62a, 62b also receive status transmissions from the IPG 100, the two coils are used in conjunction with receiver circuitry which likewise phase shifts the received modulated data signals from each coil and presents their sum to typical demodulation circuitry. 30 Because the details of transmission and reception using two orthogonal coils 62a and 62b are disclosed in detail in the '624 application, they are not reiterated here. 2245115_1 (GHMatters) 30/10/12 - 17 While the use of two orthogonal telemetry coils 62a and 62b is presently preferred, a more traditional single coil approach can be used for the telemetry and reception of data. For example, coil 62a can be used exclusively for data 5 transmissions, with coil 62b dispensed with altogether. Additionally, it should be realized that an antenna or antennas, such as might be used in other forms of wireless devices, may more generically be used in place of the telemetry coil(s) 62s and/or 62b. In other words, the means for 10 telemetry in the external controller 210 need not comprise a coil or coils per se, and coils should be understood as one type of more generic antennas which can otherwise be used. As noted earlier, the external controller 210 controls 15 both data telemetry and charging functions, and therefore the user interface (the display 265, the various buttons 270-276, etc.) provides access to and feedback from both of these functions. The software in the controller 210 (preferably implemented as microcode accessible by the controller 210's 20 microcontroller) accordingly provides logical menu options to the display 265. For example, when the controller is first turned on, the display 265 may provide selectable options for the user to either program or charge the IPG 100. If the user decides to program the IPG 100, the software would provide 25 selectable options to allow the patient options to modify therapy, such as by altering the electrodes to be stimulated, the amplitude or frequency of such stimulation, etc. If the user chooses to charge, the external controller may investigate port 225 to see if the external charging coil assembly 220 is 30 attached. If not, a suitable message might be displayed instructing the user to so attach the assembly before proceeding further in the menu. 2245115_1 (GHMatters) 30/10/12 - 18 In a preferred embodiment, the software only provides charging-related options to the user when the external charging coil assembly 220 is attached. Thus, when the external controller 210 is first turned on, a check is made as to 5 whether the assembly 220 is attached. If not, only programming (i.e., data telemetry) related options are provided to the user. If the external charging coil assembly 220 is attached, then the software assumes that charging is the priority task that it must perform, and hence only charging options are 10 provided to the user, such as an invitation to the user to start charging immediately. Likewise, if the external controller 210 senses that the external charging coil assembly 220 is attached at some point after the controller has already been turned on, the user interface options are preferably 15 changed immediately to providing charging-related selections to the user. In any event, exactly how the software is implemented vis-&-vis data telemetry and charging functionality is not particularly important to the implementation of the invention, and such software can control the user interface of 20 the external controller 210 in many different ways depending on designer and user preference. In a preferred embodiment, a data port 282 is provided to allow the external controller 210 to communicate with other 25 devices such as a computer 295. Such a data port 282 is useful for example to share data with another machine, to allow the external controller 210 to receive software updates, or to allow the external programmer 210 to receive a starter therapy program from a clinician programmer. Data port 282 can be 30 physically configured in any number of standard ways, and can be located in many different positions on the housing 240 of the external controller. Moreover, data port 282 can be configured as dictated by any number of communication protocols, such as RS323 protocol. In one advantageous 2245115_1 (GHMatters) 30/10/12 - 19 implementation, data port 282 comprises an infrared port capable of wireless communication in accordance with the IRDA (Infrared Data Association) protocol. This type of port is useful because it is electrically and mechanically sealed, 5 which reduces the possibility of potential electrical shock to the user. Another embodiment of the improved external controller/charger system 200' is illustrated in Figure 5. 10 This embodiment is otherwise similar to system 200 discussed earlier, except as concerns the various ports on the housing 215 of the external controller 210. In this system 200' the power, data, and external charging coil assembly ports 280, 282, and 225 (see Fig. 3) have been replaced by a single USB 15 port 300. The USB port 300 can comprise any USB receptacle profile, such as a micro USB plug receptacle, a mini USB plug receptacle, an A-type plug receptacle, or a B-type plug receptacle. 20 When a USB port 300 is used, the external controller 210 can be coupled to the external charging coil assembly 305 by a matching USB connector 305. Additionally, and beneficially, this same port 300 can connect with other devices, such as a computer 312 via a USB connector 310, or a AC power source 317 25 via a USB connector 315 and an AC-DC adapter 316. Therefore, using the same port 300 as that used to connect the external charging coil assembly 220, the external controller 210 can be coupled to a power source and to a data source. For example, because USB protocols call for provision of DC power, either 30 the computer 312 or the power source 317 may be used to provide power to the external controller 210, or more importantly to recharge its battery 126. Moreover, the computer 312 can be used to download programs to the external controller 210 via 2245115_1 (GHMatters) 30/10/12 - 20 the USB port, or to receive status data from the external controller 210 as already explained. Integration of the power, data, and external charging coil 5 assembly ports into a single USB port 300 benefits the design of the system 200. First, the mechanical design of the external controller 210 is made simpler, as only a single port need be provided for. Second, the design of the external controller is safer and more reliable: having only a single 10 port lessens the chance for unwanted moisture or electrical ingress inside of the housing of the controller 215, which might cause damage or shock. Because there is only a single port 300, communications 15 must be shared. For example, if when the external charging coil assembly 220 is attached, neither the computer 312 nor power source 317 can be attached. But this is not a problem, because data transfer external to the external controller 210 and/or recharging of the external controller's battery 126 20 should not be critical during a session in which a patient is recharging the battery 26 in his IPG 100. In fact, safety results from the inability to couple the external charging coil assembly 220 and the power source 317 at the same time, which means that no direct connection to AC power is possible while 25 the patient is charging. This prevents a potentially hazardous situation if the transformer 316 proves to be defective. As USB is dictated by its own communication protocol, it is a routine matter for designers to implement communications, 30 and such details do not require repeating here. Although use of a USB port 300 and accompanying USB protocol is preferred, any other type of standardized port and protocol could be used to integrate the power, data, and external charging coil functions described herein. 2245115_1 (GHMatters) 30/10/12 - 21 Although particular embodiments of the present invention have been shown and described, it should be understood that the above discussion is not intended to limit the present invention 5 to these embodiments. It will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention. Thus, the present invention is intended to cover alternatives, modifications, and equivalents that may fall 10 within the spirit and scope of the present invention as defined by the claims. In the claims which follow and in the preceding description of the invention, except where the context requires 15 otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments 20 of the invention. It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common 25 general knowledge in the art, in Australia or any other country. 2245115_1 (GHMatters) 30/10/12

Claims (23)

1. A system for communicating with an implantable medical device, comprising: 5 an external controller integrated within a single housing, the external controller comprising at least one telemetry antenna within the housing for communicating data with the implantable medical device; and an external charging coil assembly containing a charging 10 coil for providing power to the implantable medical device, wherein the assembly is attachable to and detachable from the external controller at a port on the external controller.

2. The system of claim 1, wherein the external charging coil 15 assembly is flexible.

3. The system of claim 1, wherein the external charging coil assembly does not contain a user interface. 20

4. The system of claim 1, wherein the external controller contains circuitry for energizing the charging coil.

5. The system of claim 1, wherein the port comprises a USB port. 25

6. The system of claim 1, wherein the external controller controls the charging coil.

7. The system of claim 1, wherein the external controller 30 comprises a color display.

8. The system of claim 1, wherein the at least one telemetry antenna comprises two telemetry coils each wound around axes that are orthogonal. 35

9. The system of claim 1, wherein external charging coil assembly further comprises at least one temperature sensor for 2245115_1 (GHMatters) 30/10/12 - 23 reporting at least one temperature to the external controller.

10. A system for communicating with an implantable medical device, comprising: 5 an external controller integrated within a single housing comprising a user interface, a battery, and at least one telemetry antenna within the housing for communicating data with the implantable medical device; and an external charging coil assembly containing a charging 10 coil for providing power to the implantable medical device, wherein the assembly is coupleable to and controllable by the external controller via a cable, wherein the external charging coil assembly does not contain a user interface or a battery. 15

11. The system of claim 10, wherein the external controller controls the charging coil.

12. The system of claim 10, wherein the external charging coil 20 assembly comprises at least one temperature sensor.

13. The system of claim 10, wherein the user interface comprises a display, and wherein the display comprises a color super twisted nematic (CSTN) Liquid Crystal Display (LCD), a 25 thin-film transistor (TFT) LCD, or an organic light-emitting diode (OLED) display.

14. The system of claim 10, wherein battery comprises a rechargeable battery. 30

15. A system for communicating with an implantable medical device, comprising: an external controller for communicating data with the implantable medical device, wherein the external controller 35 comprises a single port for interfacing with a source of data for the external controller, a source of power for the external controller, and an external charging coil assembly; and 2245115_1 (GHMatters) 30/10/12 - 24 an external charging coil assembly containing a charging coil for providing power to the implantable medical device, wherein the assembly is coupleable to the external controller at the port. 5

16. The system of claim 15, wherein the port communicates at least one temperature from at least one temperature sensor in the external charging coil assembly to the external controller. 10

17. The system of claim 15, wherein the port comprise a USB port.

18. The system of claim 15, wherein the power source recharges a battery in the external controller. 15

19. The system of claim 15, wherein the data source and power source comprise a computer.

20. A system for communicating with an implantable medical 20 device, comprising: an external controller integrated within a single housing comprising a user interface, a battery, and at least one telemetry antenna within the housing for communicating data with the implantable medical device, wherein the external 25 controller comprises a single USB port for interfacing with an external charging coil assembly; and an external charging coil assembly containing a charging coil for providing power to the implantable medical device, wherein the assembly is attachable to and detachable from the 30 external controller at the USB port, wherein the external controller controls the charging coil.

21. The system of claim 20, wherein the external charging coil 35 assembly does not contain a user interface or a power source.

22. The system of claim 20, wherein the user interface 22451151 (GHMatters) 30/10/12 - 25 comprises a display, and wherein the display comprises a color super twisted nematic (CSTN) Liquid Crystal Display (LCD), a thin-film transistor (TFT) LCD, or an organic light-emitting diode (OLED) display. 5

23. The system of claim 20, wherein battery comprises a Lithium-ion or a Lithium-ion polymer battery. 22451151 (GHMatters) 30/10/12