Patent Publication Number: US-11642523-B2

Title: Sinus treatment device with enhanced tip

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a Continuation-in-Part Application which claims priority benefit under 35 U.S.C. § 120 (pre-AIA) of International Patent Application No. PCT/US2018/029030, entitled “SINUS TREATMENT DEVICE WITH ENHANCED TIP,” filed Apr. 24, 2018. International Patent Application No. PCT/US2018/029030 claims priority benefit from U.S. Provisional Patent Application No. 62/491,793, entitled “SINUS DEVICE WITH ADAPTIVE CIRCUIT,” filed Apr. 28, 2017. International Patent Application No. PCT/US2018/029030 also claims priority benefit from U.S. Provisional Patent Application No. 62/559,792, entitled “TREATMENT DEVICE INCLUDING WIRELESS INTERFACE AND USER APPLICATION,” filed Sep. 18, 2017. International Patent Application No. PCT/US2018/029030 also claims priority benefit from U.S. Provisional Patent Application No. 62/560,120, entitled “ADAPTIVE TRIGGER FOR A MICROCURRENT STIMULATION DEVICE,” filed Sep. 18, 2017. Each of the foregoing applications, to the extent not inconsistent with the disclosure herein, is incorporated by reference. 
    
    
     BACKGROUND 
     Every year, millions of people suffer from sinus pain, stuffiness, and drainage associated with colds, viruses, rhinosinusitis, allergies, flus, inflammation, and infection. Sinus pain can cause symptoms consistent with headaches as nasal cavities become infected, swollen, and/or inflamed. Many sinus pain patients resort to medications that can be taken orally but which also have significant side effects including drowsiness, dry mouth, nausea, and difficulty sleeping. 
     What is needed is an approach that can alleviate sinus symptoms without the negative effects of conventional sinus medications. 
     SUMMARY 
     According to an embodiment, a sinus treatment device includes a housing configured to be held in a hand, a return electrode operatively coupled to the housing, and a conductive tip. The sinus treatment device includes sinus treatment circuitry positioned within the housing and configured to detect sinus treatment locations on a face of a user based on an impedance between the conductive tip and the return electrode and to pass a treatment current between the conductive tip and the return electrode via the treatment location on the face of the user. The sinus treatment device includes a resilient member coupled to the conductive tip and configured to enable the conductive tip to resiliently depress toward the housing. 
     According to an embodiment, a sinus treatment device includes a housing configured to be held in a hand of a user, a conductive tip coupled to the housing and having a distal surface distal to the housing and a dielectric covering positioned on the distal surface and defining a covered portion of the distal surface and an exposed portion of the distal surface. The sinus treatment device includes a return electrode operatively coupled to the housing and sinus treatment circuitry positioned within the housing. The sinus treatment circuitry is configured to detect sinus treatment locations on a face of the user based on an impedance between the conductive tip and the return electrode and to pass a treatment current between the exposed portion of the distal surface of the conductive tip and the return electrode via the treatment location on the face of the user. 
     According to an embodiment, a method includes detecting an impedance between a conductive tip of a sinus treatment device and a return electrode of the sinus treatment device, initiating a treatment mode of the sinus treatment device when the impedance drops below a threshold by passing a sinus treatment current between the conductive tip and the return electrode, and gradually increasing a magnitude of the sinus treatment current during the treatment mode. 
     According to an embodiment, a method includes detecting, during a detection mode of a sinus treatment device, an impedance between a conductive tip of the sinus treatment device and a return electrode of the sinus treatment device, initiating a treatment mode of the sinus treatment device responsive to the impedance, and passing, during the treatment mode, a treatment current including a series of current spikes. The method includes gradually increasing a magnitude of the current spikes during the treatment mode until the magnitude reaches a full treatment level. 
     According to an embodiment, a microcurrent sinus treatment device includes a circuit configured to deliver a sequence of voltage pulses carrying a therapeutic current, and a therapeutic electrode operatively coupled to the circuit. The therapeutic electrode may be configured to apply the sequence of voltage pulses to a user&#39;s skin surface adjacent to one of a plurality of nerve nodes subjacent to the user&#39;s skin surface. The therapeutic electrode may be in electrical continuity with a therapeutic current output node of the circuit. The microcurrent sinus treatment device includes a hand holdable case configured to substantially contain active portions of the circuit. The hand holdable case includes a forward end terminating in the therapeutic electrode, and a return electrode comprising a portion of or disposed on a surface of the hand holdable case. The return electrode may be in electrical continuity with a current return node of the circuit. The hand holdable case also includes a dielectric spacer disposed between the therapeutic electrode and the return electrode, and a rearward portion of the hand holdable case terminating at an end a distance less than about four inches from the therapeutic electrode tip. The dielectric spacer and the return electrode may form a tapered surface narrowing toward the therapeutic electrode from a point of maximum girth disposed between the forward end and the rearward end of the hand holdable case. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1 A  is a perspective view of a handheld sinus treatment device, according to an embodiment of the disclosure. 
         FIG.  1 B  is a top view of the handheld sinus treatment device of  FIG.  1 A , according to an embodiment of the disclosure. 
         FIG.  1 C  is a bottom view of the handheld sinus treatment device of  FIG.  1 A , according to an embodiment of the disclosure. 
         FIG.  2    is an illustration of a handheld sinus treatment device providing sinus relief treatment to highlighted treatment areas adjacent to the sinuses of a user, according to an embodiment of the disclosure. 
         FIGS.  3 A and  3 B  illustrate nasal pathways and associated nerves that a sinus treatment device may be applied to, according to an embodiment of the disclosure. 
         FIG.  4    is a block diagram of a sinus treatment device, according to an embodiment of the disclosure. 
         FIG.  5    illustrates an example adaptive output circuit for use with a sinus treatment device, according to an embodiment of the disclosure. 
         FIG.  6    is a graph of a treatment current vs time, according to an embodiment of the disclosure. 
         FIG.  7    is a graph of a treatment current vs time including a gradually increasing treatment current, according to an embodiment of the disclosure. 
         FIG.  8    is an enlarged view of a portion of a sinus treatment device, according to an embodiment of the disclosure. 
         FIG.  9 A  is an enlarged view of a portion of a sinus treatment device including a resilient member, according to an embodiment of the disclosure. 
         FIGS.  9 B and  9 C  are enlarged views of a portion of a sinus treatment device including a spring, according to an embodiment of the disclosure. 
         FIGS.  9 D and  9 E  are enlarged views of a portion of a sinus treatment device including a flexible membrane, according to an embodiment of the disclosure. 
         FIG.  10    is a flow chart of a process for operating a sinus treatment device, according to an embodiment of the disclosure. 
         FIG.  11    is a flow chart of a process for operating a sinus treatment device, according to an embodiment of the disclosure. 
         FIG.  12    shows several views of a microcurrent sinus treatment device, according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. Other embodiments may be used and/or other changes may be made without departing from the spirit or scope of the disclosure. 
       FIG.  1 A  is a perspective view of a handheld sinus treatment device  102 , according to an embodiment. The handheld sinus treatment device  102  includes a body  106 , a conductive tip  108 , a return electrode  110 , and a charging port  112 , according to an embodiment. 
     According to an embodiment, the handheld sinus treatment device  102  is configured to provide sinus treatment to a user. The user holds the sinus treatment device  102  in one hand, with the hand contacting the return electrode  110 , places the conductive tip  108  against the skin in the sinus region (see  FIGS.  3 A- 3 B ) and glides the conductive tip  108  across the skin until the handheld sinus treatment device  102  detects a treatment location. When the handheld sinus treatment device  102  detects a treatment location, the handheld sinus treatment device  102  directs the user to hold the handheld sinus treatment device  102  still, and passes a treatment current between the conductive tip  108  and the return electrode  110 . The treatment current passes through a nerve at the treatment location, thereby providing sinus relief to the user. 
     According to an embodiment, the body  106  is a rigid casing or housing. The body  106  has a shape that enables the user of the handheld sinus treatment device  102  to securely grip and comfortably hold the handheld sinus treatment device  102  during operation of the handheld sinus treatment device  102 . 
     In one embodiment, the body  106  can be made from a material that is not electrically conductive. Alternatively, the body  106  can be made from a material that is electrically conductive, or can include portions that are electrically conducive, according to an embodiment. The body  106  can be made from a material that has low thermal conductivity. The body  106  is configured to protect sensitive electronic circuitry positioned within the body  106 , as is described in more detail with relation to  FIGS.  4 - 5   . 
     According to an embodiment, the conductive tip  108  is an electrical conductor placed at a tip of the body  106 . The conductive tip  108  can include a rounded shape at a point of contact with the skin of the user such that the conductive tip  108  can be placed against the skin of the user comfortably without piercing or scratching the skin. Furthermore, the shape and material of the conductive tip  108  can be selected to enable the user to comfortably glide the conductive tip  108  along the skin of the user&#39;s face adjacent to sinuses of the user. The conductive tip  108  is a treatment electrode, according to an embodiment. 
     According to an embodiment, the return electrode  110  includes an electrically conductive material positioned at various locations on or in the body  106 . The return electrode  110  can be positioned in the body  106  at positions selected so that when the user holds the handheld sinus treatment device  102  in the user&#39;s hand, the user&#39;s hand is in contact with the return electrode  110  on one or more locations on the body  106 . According to an embodiment, the return electrode  110  can include a conductive polycarbonate. 
     According to an embodiment, the charging port  112  is positioned at the rear of the body  106  of the handheld sinus treatment device  102 . The charging port  112  is configured to receive a charging cable. When the charging cable is connected to the charging port  112 , the internal battery of the handheld sinus treatment device  102  is recharged. Additionally, or alternatively, the charging port  112  can be a power supply port configured to connect to a power cable that provides power to the handheld sinus treatment device  102  while the user is using the handheld sinus treatment device  102 . The charging port  112  can be a micro USB port, a USB 2.0 port, a USB 3.0 port, a USB C port, or any other kind of port that can be utilized to charge the battery of the handheld sinus treatment device  102 , or to otherwise provide power to the handheld sinus treatment device  102 . Additionally, or alternatively, the handheld sinus treatment device  102  can include wireless charging capability. For example, the handheld sinus treatment device  102  can include circuitry that enables inductive charging of the battery of the handheld sinus treatment device  102  such that when the handheld sinus treatment device  102  is positioned on a charging dock, the battery is recharged by inductive charging. 
       FIG.  1 B  is a top view of a handheld sinus treatment device  102 , according to an embodiment. The top view of the handheld sinus treatment device  102  illustrates the body  106 , the conductive tip  108 , the return electrode  110 , the charging port  112 , indicators  114 , a sensitivity setting button  116 , a power button  118 , and a low battery indicator  120 . 
     According to an embodiment, the indicators  114  can provide an indication of the sensitivity level of the handheld sinus treatment device  102 . The sensitivity level corresponds to a sensitivity setting for detecting treatment areas adjacent to the sinuses of the user. The indicators  114  can include multiple LED indicators. The handheld sinus treatment device  102  can illuminate a number of the sensitivity level indicator LEDs  114  to indicate a sensitivity level of the handheld sinus treatment device  102  during a detection mode. A greater number of illuminated indicator LEDs  114  can correspond to a higher sensitivity level. A lesser number of illuminated indicator LEDs  114  can correspond to a lower sensitivity level. Alternatively, other schemes for illuminating LEDs to indicate a sensitivity level of the detection mode of the handheld sinus treatment device  102  can be utilized. Additionally, the indicators  114  can include indicators other than LEDs. For example, the indicators  114  can include various types of lights, a display panel, or other types of indicators capable of providing an indication of the sensitivity level of the handheld sinus treatment device  102  during a detection mode of the handheld sinus treatment device  102 . According to an embodiment, the indicators  114  can also signal that a treatment location has been identified, that treatment stimulation is currently being provided, that another treatment location should be identified, or other parameters of operation of the handheld sinus treatment device  102 . 
     According to an embodiment, the sensitivity setting button  116  is configured to enable the user to adjust the sensitivity of the handheld sinus treatment device  102  during a detection mode. The user can manipulate the sensitivity setting button  116  in order to increase or decrease the sensitivity of the handheld sinus treatment device  102 . For example, the user can press the sensitivity setting button  116  to adjust the sensitivity of the handheld sinus treatment device  102 . Additionally, or alternatively, the user can toggle or slide the sensitivity setting button  116  in order to adjust the sensitivity of the handheld sinus treatment device  102 . Additionally, or alternatively, the sensitivity setting button  116  can include multiple buttons for adjusting the sensitivity of the handheld sinus treatment device  102 . A first button can be used to decrease the sensitivity. A second button can be used to increase the sensitivity. Additionally, or alternatively, the handheld sinus treatment device  102  can include a touchscreen that enables the user to adjust the sensitivity of the handheld sinus treatment device  102 . 
     According to an embodiment, the power button  118  is configured to enable the user to turn the handheld sinus treatment device  102  on or off. For example, if the handheld sinus treatment device  102  is currently off, then the user can turn the handheld sinus treatment device  102  on by pressing, toggling, sliding, or otherwise manipulating, the power button  118 . If the handheld sinus treatment device  102  is currently on, then the user can turn the handheld sinus treatment device  102  off by pressing, toggling, sliding, or otherwise manipulating the power button  118 . Alternatively, the sensitivity setting button  116  and the power button  118  can be implemented in a single button or switch that can adjust the sensitivity or turn the handheld sinus treatment device  102  on or off based on a length of a button press, a number of button presses, or other types of manipulations of the single button. 
     According to an embodiment, the low battery indicator  120  can provide an indication of a state of charge of the battery of the handheld sinus treatment device  102 . The low battery indicator  120  can include one or more LEDs. When the battery of the handheld sinus treatment device  102  is low, one or more LEDs of the low battery indicator  120  can become illuminated. If the low battery indicator  120  includes a single LED, then the single LED can become illuminated when the battery is nearing depletion. Conversely, the single LED may not be illuminated when the battery is not nearing depletion. Alternatively, when the battery is nearing depletion, a first LED of a first color can be illuminated to indicate that the battery is nearing depletion. If the battery is not nearing depletion, then a second LED of a second color can be illuminated indicating that the battery is not nearing depletion. 
     According to an embodiment, portions of the return electrode  110  are positioned on the sides of the body  106  of the handheld sinus treatment device  102 . When the user grips the handheld sinus treatment device  102  such that a thumb of the user is in a position to manipulate the sensitivity setting button  116  and the power button  118 , the palm and/or fingers of the hand of the user will be in contact with the portion of the return electrode  110  positioned on the sides of the body  106  of the handheld sinus treatment device  102 . 
       FIG.  1 C  is a bottom view of the handheld sinus treatment device  102  of  FIG.  1 B , according to an embodiment. The bottom view of the handheld sinus treatment device  102  illustrates a portion of the return electrode  110  positioned on the bottom portion of the body  106  of the handheld sinus treatment device  102 . The positioning of a portion of the return electrode  110  on the bottom of the body  106  of the handheld sinus treatment device  102  further ensures that when the user holds the handheld sinus treatment device  102  in the user&#39;s hand, the user&#39;s hand will be in contact with the return electrode  110 . 
       FIG.  2    is an illustration of a face  226  of a user of the handheld sinus treatment device  102  highlighting treatment areas  228 . According to an embodiment, the treatment areas  228  correspond to nerve nodes. The nerve nodes are treatment locations  228  at which sinus nerves pass through the skull. 
     According to an embodiment, the user uses the handheld sinus treatment device  102  by holding the body  106  in one hand such that the user&#39;s hand is in contact with portions of the return electrode  110 . The user then places the conductive tip  108  on the skin adjacent to the sinuses and glides the conductive tip  108  over the skin during a detection mode of the handheld sinus treatment device  102 . In the detection mode, the handheld sinus treatment device  102  detects the treatment location  228 , corresponding to the location of a nerve node beneath the skin. When the handheld sinus treatment device  102  detects the treatment location  228  of a nerve node beneath the skin, the handheld sinus treatment device  102  can enter a treatment mode. 
     In one embodiment, the handheld sinus treatment device  102  detects treatment locations  228  by detecting an impedance between the conductive tip  108  and the return electrode  110 . Treatment locations  228  are characterized by a lower impedance than surrounding areas due to enhanced conductivity of nerves. 
     According to an embodiment, in the treatment mode, the handheld sinus treatment device  102  provides treatment stimulation to the treatment location  228 , corresponding to the nerve that is located during the detection mode. The handheld sinus treatment device  102  can provide treatment stimulation to the treatment location  228  by providing electrical stimulation to the treatment location  228 . The electrical stimulation can affect the nerve node in such a way that the user experiences relief from troubling sinus symptoms such as pain, congestion, inflammation, or other unpleasant symptoms. 
     According to an embodiment, the handheld sinus treatment device  102  is a transcutaneous electrical nerve stimulation (TENS) device. The handheld sinus treatment device  102  applies electrical treatment stimulation in the form of a treatment current having selected characteristics. The treatment current can have an average magnitude that is multiple orders of magnitude lower than common TENS devices. According to an embodiment, the treatment current does not have a DC component, but is characterized by current spikes of alternating polarity. According to an embodiment, the treatment stimulation is provided at each treatment location  228  for a period of time between 2-10 seconds. 
     According to an embodiment, the handheld sinus treatment device  102  applies the treatment current by applying a stimulation voltage between the conductive tip  108  and the return electrode  110 . 
     According to an embodiment, the conductive tip  108  is the active electrode of a monopolar design. The housing/body  106  of the handheld sinus treatment device  102  may serve as the return electrode  110  when return electrodes  110  are integrated into the body  106 . A user&#39;s hand holding the handheld sinus treatment device  102  completes the electrical path from the conductive tip  108  to the return electrode(s)  110  in that currents may travel from the conductive tip  108 , through the nasal area of the user and down to the hand of the user that is contacting the return electrode(s)  110 , in an embodiment. These currents may be referred to as “treatment currents” in this disclosure. 
     According to an embodiment, in the detection mode, the user presses the conductive tip  108  to the skin and the handheld sinus treatment device  102  initiates a low-frequency circuit that is maintained at a constant current. The handheld sinus treatment device  102  may use the current to calculate the impedance in the path between the tissue at the conductive tip  108  and the hand in contact with the handheld sinus treatment device  102 . The handheld sinus treatment device  102  remains in the detection mode until the detection current indicates that the impedance is below a threshold impedance. The position of the conductive tip  108  when the impedance is below the threshold impedance corresponds to a treatment area  228 . The treatment area  228  corresponds to a nerve node area. When the handheld sinus treatment device  102  identifies a treatment area  228  based on the calculated impedance, the handheld sinus treatment device  102  can enter the treatment mode and can deliver treatment stimulation to the identified treatment area  228 . 
     According to an embodiment, the handheld sinus treatment device  102  can indicate to the user that the handheld sinus treatment device  102  is in the treatment mode and that the user should hold the conductive tip  108  at the treatment location  228  for a selected period of time. According to an embodiment, the handheld sinus treatment device  102  can indicate the transition between the detection mode and the treatment mode by the indicators  114 . The indicators  114  can include one or more LEDs that can provide an illumination scheme that indicates whether the handheld sinus treatment device  102  is in the detection mode or the treatment mode. According to an embodiment, the handheld sinus treatment device  102  can indicate that the handheld sinus treatment device  102  is in the treatment mode via haptic feedback (vibration). According to an embodiment, the handheld sinus treatment device  102  can indicate whether the handheld sinus treatment device  102  is in the detection mode, the treatment mode, or transitioning between the detection and the treatment modes by a combination of haptic feedback and the LED indicators  114 . According to an embodiment, when the handheld sinus treatment device  102  enters the treatment mode as indicated by one or more of the LED indicators  114  and haptic feedback, the user holds the handheld sinus treatment device  102  in place until the treatment period has passed as indicated by cessation of haptic feedback and the LED indicators  114  (approximately 8 seconds in one example). 
     According to an embodiment, once the treatment period ends, the handheld sinus treatment device  102  resets to detection mode. The user then may continue to glide the handheld sinus treatment device  102  along the indicated path until reaching the next treatment area  228  as identified based on impedance calculations. The user may adjust the impedance sensitivity of the handheld sinus treatment device  102 , in one embodiment. Changes in sensitivity adjust the impedance threshold at which the handheld sinus treatment device  102  will enter treatment mode. Changes in sensitivity do not change the output current, in one embodiment. 
     In one embodiment of a treatment circuit of the disclosed handheld sinus treatment device  102 , the constant current stimulation output is approximately 1 Hz-1000 Hz, bi-phasic, no DC component signal with an average current less than 1000 μA over a resistive load of 10K-100KΩ. The signal is presented to the user by means of the conductive tip  108 , in one embodiment. According to an embodiment, the spring-loaded conductive tip  108  activates the circuit and gently ramps the current to provide maximal comfort to the user. 
     According to an embodiment, constant current stimulation circuit output is directed to the conductive tip  108  and returned to the circuit by way of the return electrode  110  (metallized portions of the enclosure). When the circuit is completed by the user pressing the device conductive tip  108  to the face  226 , a microcontroller monitors the resulting treatment current and controls the stimulation voltage (across the conductive tip  108  and the return electrode  110 ) to maintain the desired current, in one embodiment. The impedance of the circuit is then calculated and monitored by the microcontroller. In the event that the impedance falls below a specified threshold, which is indicative of a treatment location  228 , the microcontroller presents a treatment prompt through a user interface (UI), in one embodiment. According to an embodiment, the user is instructed to maintain the conductive tip  108  location until the treatment prompt has timed out. After treatment time out, the user is instructed to slowly move the conductive tip  108  to the next detected treatment location  228 , in one embodiment. 
     According to an embodiment, the sensitivity level setting determines the impedance threshold at which the handheld sinus treatment device  102  will signal the user to detection of a treatment location  228 . The treatment sensitivity threshold may be increased to compensate for higher impedance associated with dry skin or the presence of makeup, in one embodiment. Upon detection of a treatment location  228 , the haptic motor starts to vibrate and the sensitivity level indicator LEDs  114  flash for a pre-programmed period of time, in one embodiment. If the calculated impedance increases above the threshold (conductive tip  108  removed from the face  226  or moved to a higher impedance location on the face  226 ), the treatment session may be terminated. 
     In one embodiment, the handheld sinus treatment device  102  is used as a handheld microcurrent TENS device used for the temporary relief of sinus pain. The handheld sinus treatment device  102  uses an average treatment current that is several orders of magnitude smaller than that of previously cleared TENS devices, in one embodiment. In one embodiment, the handheld sinus treatment device  102  is a sinus treatment device designed to provide transcutaneous nerve stimulation to the regional areas associated with the sinuses, and current levels are attuned to those appropriate for facial treatments, as seen in predicate facial toners. 
     The sinus treatment device  102  is held in the hand, with the conductive tip  108  of the handheld sinus treatment device  102  applied to the skin on the outside of the sinus passages. In one embodiment, the conductive tip  108  is the active electrode of a monopolar design. The housing/body  106  of the handheld sinus treatment device  102  may serve as the return electrode  110  when return electrodes  110  are integrated into the body  106 . A user&#39;s hand holding the sinus treatment device  102  completes the electrical path from the conductive tip  108  to the return electrode(s)  110  in that treatment currents may travel between the conductive tip  108  and the return electrode  110  through the nasal area. The treatment current can be passed in either direction between the conductive tip  108  and the return electrode  110  through the body of the user, according to an embodiment. The treatment current can alternate directions during the treatment mode, according to an embodiment. 
     In one embodiment, when the user turns the handheld sinus treatment device  102  “ON” and presses the conductive tip  108  to the skin, the handheld sinus treatment device  102  initiates a low-frequency circuit that is maintained at a constant detection current. The handheld sinus treatment device  102  may use the detection current to calculate the impedance in the path between the tissue at the conductive tip  108  and the hand in contact with the handheld sinus treatment device  102 . In one embodiment, if the calculated impedance is above an impedance threshold, the handheld sinus treatment device  102  is in “detection” mode. Conversely, in one embodiment, when the impedance falls below the impedance threshold, the handheld sinus treatment device  102  enters a “treatment” mode. In one embodiment, in the treatment mode the treatment current is has a greater magnitude than the current used in the detection mode. 
     In one embodiment, the user is instructed to glide the conductive tip  108  of the handheld sinus treatment device  102  along the skin, in accordance with an embodiment of the disclosure. The switch (transition) from detection mode to the treatment mode is signaled to the user via haptic (vibration) feedback and blinking of the indicator LEDs  114 , in one embodiment. The user then holds the handheld sinus treatment device  102  in place until the treatment period has passed as indicated by cessation of haptic and LED indicators  114  (approximately 8 seconds in one example), in one embodiment. 
     In one embodiment, once the treatment period ends, the handheld sinus treatment device  102  resets to detection mode. The user then may continue to glide the handheld sinus treatment device  102  along the indicated path until reaching the next low-impedance area. The user may adjust the impedance sensitivity of the handheld sinus treatment device  102 , in one embodiment. Changes in sensitivity adjust the impedance threshold at which the handheld sinus treatment device  102  will enter treatment mode. Changes in sensitivity do not change the treatment current, in one embodiment. 
     In one embodiment, the sensitivity setting button  116  may allow a user to toggle through different sensitivity levels that may be indicated by the example illustrated three indicator LEDs  114 , in  FIGS.  1 A- 1 C . In one embodiment, an overcoat/insulator may cover the body  106  of the handheld sinus treatment device  102  except for where the return electrode  110  provides an electrical path. 
     In one embodiment, the conductive tip  108  includes an elastomeric material intended to minimize point pressure against the face  226  of the user. Various elastomers including silicone, fluorine-substituted silicones, natural rubber, vulcanized rubber, latex, latex derivatives, etc. may be used alone or in combination to form a support structure of the conductive tip  108 . In another embodiment, a non-elastomeric dielectric material such as a polymer, polymer combination, or glass may be used alone or in combination to form the support structure of the active electrode. The support structure may be formed to have a relatively low thermal conductivity and/or may have a smooth radius to reduce point pressure against the skin of the user. Various conductive fibers or particles such as gold, silver, stainless steel, carbon fiber, carbon nanotubes, and/or alternating bond length (electron-conjugated) polymers are contemplated as current carriers supported by a dielectric support structure. 
     In one embodiment, the handheld sinus treatment device  102  includes a spring-loaded conductive tip  108  and the conductive tip  108  is a small surface area metalized feature (tip) of the enclosure that is applied to the treatment regions of the face  226 . In one embodiment, a microswitch initiates the therapy circuit when the conductive tip  108  is depressed. The handheld sinus treatment device  102  may include a microprocessor, microcontroller, a battery, and a transformer/voltage step-up circuit. In one embodiment, the return electrode  110  is a large surface area metalized region of the enclosure that is in contact with the user&#39;s hand. 
     In one embodiment, the user interface of the handheld sinus treatment device  102  includes an LED treatment indicator  114  (e.g., LEDs  114 ), a sensitivity level adjustment button  116 , and a haptic feedback circuit. The LED sensitivity level indicates selected sensitivity levels in addition to low battery and charge status, an on/off button with integrated LED(s)  118  to indicate “on” or “off” state, and a haptic feedback circuit. 
     In one embodiment, the handheld sinus treatment device  102  includes an overcoat that is electrically insulated. The overcoat may cover a portion of the metalized return electrode  110  so long as a portion (e.g., 10%) of the return electrode  110  is exposed. In one embodiment, the handheld sinus treatment device  102  includes a battery charging port  112  and circuit to charge an internal battery. 
     As described above, the handheld sinus treatment device  102  may be used as a TENS device that applies microamp electrical stimulation to facial nerves around the sinuses which are the regions around the nose and the supraorbital region of the eye. The locations of the low impedance points in the facial skin correlate strongly with various foramina (holes) through which major nerve fibers pass from the sinus passages, through the skull, to areas near the skin. 
       FIGS.  3 A and  3 B  illustrate nasal pathways and associated nerves that the handheld sinus treatment device  102  may be applied to by a user to facilitate treatment/therapy. 
     In one embodiment of a treatment circuit of the disclosed handheld sinus treatment device  102 , the constant current stimulation output is approximately 1 Hz-1000 Hz, bi-phasic, no DC component signal with an average current −less than 1000 μA over a resistive load of 10K-100KΩ. The signal is presented to the user by means of the monopolar electrode, in one embodiment. In one embodiment, the spring-loaded conductive tip  108  activates the circuit and gently ramps the current to provide maximal comfort to the user. 
     In one embodiment, constant current stimulation circuit output is directed to the conductive tip  108  (the device tip  108 ) and returned to the circuit by way of the return electrode  110  (metallized portions of the enclosure). When the circuit is completed by the user pressing the device conductive tip  108  to the face  226 , a microcontroller monitors the resulting treatment current and controls the stimulation voltage (across the conductive tip  108  and return electrode  110 ) to maintain the desired current, in one embodiment. The impedance of the circuit is then calculated and monitored by the microcontroller. In the event that the impedance falls below a specified threshold, which is indicative of a treatment location  228 , the microcontroller presents a treatment prompt through the user interface (UI), in one embodiment. In one embodiment, the user is instructed to maintain the conductive tip  108  location until the treatment prompt has timed out. After treatment time out, the user is instructed to slowly move the conductive tip  108  to the next detected treatment location  228 , in one embodiment. 
     In one embodiment, the sensitivity level setting determines the impedance threshold at which the handheld sinus treatment device  102  will signal the user to detection of a treatment location  228 . The treatment sensitivity threshold may be increased to compensate for higher impedance associated with dry skin or the presence of makeup, in one embodiment. Upon detection of a treatment location  228 , the haptic motor starts to vibrate and the sensitivity level indicator LEDs  116  flash for a pre-programmed period of time, in one embodiment. If the calculated impedance increases above the threshold (conductive tip  108  removed from the face  226  or moved to a higher impedance location on the face  226 ), the treatment session may be terminated. 
       FIG.  4    is a block diagram of the handheld sinus treatment device  102 , according to an embodiment. The handheld sinus treatment device  102  includes a sinus treatment circuitry (or current output circuit)  429 , the charging port  112 , the indicators  114 , a user interface  430 , a memory  432 , a microcontroller  434 , a motor  437 , and a battery  438 . The current output circuit  429  includes the conductive tip  108  and the return electrode  110 . The handheld sinus treatment device  102  utilizes these components to provide effective sinus relief treatments to the user. 
     According to an embodiment, the conductive tip  108  and the return electrode  110  cooperate together to provide both detection currents and treatment stimulation. Detection and treatment currents are passed between the conductive tip  108  and the return electrode  110  through the body of the user. In particular, the conductive tip  108  is positioned in contact with the user&#39;s skin to the sinus areas of the user. The return electrode  110  is in contact with the user&#39;s hand as the user holds the handheld sinus treatment device  102 . The detection and treatment currents pass between the conductive tip  108  and the return electrode  110  via the hand, body, and facial skin of the user. 
     According to an embodiment, the indicators  114  provide indications to the user as to the current mode of operation of the handheld sinus treatment device  102 . The indicators  114  can include one or more LEDs that can be illuminated in selected ways to indicate whether the handheld sinus treatment device  102  is powered on, whether the handheld sinus treatment device  102  is in a treatment mode, whether the handheld sinus treatment device  102  is in a detection mode, whether the handheld sinus treatment device  102  awaits user input, or indications of other types of functionality of the handheld sinus treatment device  102 . According to an embodiment, the indicators  114  can include a display capable of outputting text or images to indicate to the user the various functions of the handheld sinus treatment device  102 . 
     According to an embodiment, the user interface  430  includes various components that enable the user to control functionality of the handheld sinus treatment device  102 . The user interface  430  can include the power on-off button  118 , the sensitivity setting button  116 , or other kinds of buttons, switches, touchscreens, or input controls that enable the user to control functionality of the handheld sinus treatment device  102 . The user can manipulate the user interface  430  in order to control the functionality of the handheld sinus treatment device  102 . 
     According to an embodiment, the memory  432  stores data related to the functionality of the handheld sinus treatment device  102 . The memory  432  can include software instructions by which the various functionalities of the handheld sinus treatment device  102  can be implemented. The memory  432  can include reference impedance values and/or threshold impedance values. The reference and threshold impedance values can be utilized in the detection mode of the handheld sinus treatment device  102 . The memory  432  can include data indicating previously detected treatment locations  228 . The memory  432  can include other settings such as treatment lengths, treatment stimulation strengths, frequencies of treatments, or other settings including default settings and user selected settings for operation of the handheld sinus treatment device  102 . The memory  432  can include one or more of EEPROMs, flash memory, ROMs, SRAM, DRAM, or other kinds of computer readable media capable of storing instructions that can be executed by the microcontroller  434 . 
     According to an embodiment, the motor  437  enables the handheld sinus treatment device  102  to provide haptic feedback to the user. For example, during a treatment mode in which the handheld sinus treatment device  102  provides stimulation treatment to a treatment area  228 , the motor  437  can cause the handheld sinus treatment device  102  to vibrate mildly to indicate to the user that the handheld sinus treatment device  102  is in the treatment mode. The motor  437  can cease the vibration to indicate that the handheld sinus treatment device  102  is no longer in the treatment mode. The motor  437  can generate vibrations to provide a variety of types of indications to the user of the handheld sinus treatment device  102 . 
     According to an embodiment, the battery  438  provides power to the handheld sinus treatment device  102 . The battery  438  can include a rechargeable battery  438  that enables the user to recharge the battery  438  after the battery  438  has become depleted through use. The battery  438  can be a lithium-ion battery, a NiCad battery, a carbon zinc battery, an alkaline battery, a nickel metal hydride battery, or other types of batteries. 
     According to an embodiment, the charging port  112  enables the user to recharge the battery  438 . For example, the charging port  112  can be configured to receive a charging cable that connects the charging port  112  to a power source. The charging port  112  can include a micro USB port, a USB 2.0 port, a USB 3.0 port, a USB C port, or other types of charging ports. According to an embodiment, the charging port  112  enables charging and data transmission. When a charging cable is plugged into the charging port  112 , the battery  438  can be charged and data can be received or transmitted over the charging cable via the charging port  112 . According to an embodiment, the handheld sinus treatment device  102  can operate while a charging cable is attached to the charging port  112 . Thus, if the battery  438  is depleted, the user can attach a charging cable to the charging port  112  and can operate the handheld sinus treatment device  102  from power received via the charging port  112 . 
     According to an embodiment, the microcontroller  434  controls the functionality of the other components of the handheld sinus treatment device  102 . The microcontroller  434  is communicatively coupled to the conductive tip  108 , the return electrode  110 , the indicators  114 , the memory  432 , the user interface  430 , and the charging port  112 . 
     According to an embodiment, the microcontroller  434  executes the software instructions stored in the memory  432  to implement the various modes of functionalities of the handheld sinus treatment device  102 . The microcontroller  434  causes the conductive tip  108  and the return electrode  110  to pass the detection currents in the detection mode, and to pass the treatment currents in the treatment mode. The microcontroller  434  controls the indicators  114  to indicate the various modes of functionalities of the handheld sinus treatment device  102 . The microcontroller  434  communicates with the user interface  430  to enable the user to select various modes of operation of the handheld sinus treatment device  102 . 
       FIG.  5    illustrates an example sinus treatment circuitry  500  for use with the handheld sinus treatment device  102 , according to an embodiment of the disclosure. The sinus treatment circuitry  500  is positioned within the housing/body  106 , according to one embodiment. The sinus treatment circuitry  500  includes a microcontroller  434  including a memory  432  and an analog-to-digital converter (ADC)  593 . In the illustrated embodiment of  FIG.  5   , the sinus treatment circuitry  500  also includes a stimulation driver stage and a peak detector. 
     In one embodiment, the stimulation driver stage is coupled to apply a stimulation voltage between the conductive tip (active electrode TP 2 ) and the return electrode  110  (not illustrated in  FIG.  5   ). In the illustrated embodiment, the stimulation driver stage includes a digital-to-analog converter (DAC), an amplifier, a transformer, and a capacitor. In one embodiment, the DAC (U 6 ) is coupled to generate an analog voltage (pin  1  of U 6 , VOUT) in response to a digital instruction from the microcontroller  434  received via the MOSI (Master Out Slave In) communication channel of pin  4  of U 6 . 
     In the illustrated embodiment, the amplifier includes transistors Q 5  and Q 6  and is coupled to generate an amplified analog voltage (emitter node of Q 5 ) in response to receiving the analog voltage from the DAC (U 6 ). 
     In the illustrated embodiment, the transformer T 1  includes a primary side (nodes  3  and  4 ) and a secondary side (nodes  1  and  2 ). The conductive tip (active electrode TP 2 ) is coupled to node  1  of the secondary side of the transformer T 1 , in the illustrated embodiment. 
     In the illustrated embodiment, capacitor C 10  is coupled between the amplifier and a primary side of the transformer T 1  to block the DC (direct current) portions of the amplified analog signal. 
     In one embodiment, the peak detector includes a diode element, a buffer circuit, and a sample and hold circuit. In the illustrated embodiment, the diode element is D 7 . In one embodiment, the buffer circuit is coupled to output a peak treatment current signal. In one embodiment, the peak detector is coupled to generate a peak treatment current signal on the node  1  output of op-amp U 5  in response to receiving a stimulation signal from the conductive tip TP 2 . In the illustrated embodiment, the stimulation signal may travel from the conductive tip TP 2  to node  2  of the transformer T 1  via node  1  of the transformer T 1 . 
     In one embodiment, the sample and hold circuit is coupled between the diode element (e.g., D 7 ) and the buffer circuit and the diode element is coupled between the secondary side of the transformer and the sample and hold circuit. In the illustrated embodiment, the sample and hold circuit includes resistors R 26  and capacitor C 11 . 
     In one embodiment, the microcontroller  434  is coupled to receive the peak treatment current signal (SENSE) from the peak detector and coupled to the stimulation driver stage for adjusting the stimulation voltage in response to the peak treatment current signal. In one embodiment, the microcontroller  434  dynamically adjusts the stimulation voltage to keep the peak treatment current signal at a constant value. In one embodiment, microcontroller  434  includes ADC  593  coupled to sample the peak treatment current signal and drive the digital instruction to the DAC U 6  (via MOSI communication channel) to keep the peak treatment current signal at the constant value. 
     The sinus treatment circuitry  500  of  FIG.  5    provides a means to maintain a nearly constant (and comfortable) treatment current in response to varying resistance or impedance. Turning to a more specific description of an embodiment of sinus treatment circuitry  500 , a digital-to-analog converter (DAC) U 6  receives commands from the microcontroller  434  to generate a square wave with a variable amplitude of 0 to +Vcc volts. The DAC U 6  output is current limited by R 22  and is used to drive a push-pull output power stage comprised of Q 5  and Q 6 , in the illustrated embodiment. The output of the push-pull stage is AC coupled by capacitor C 10  and drives the primary side of a step-up transformer T 1 . Capacitor C 10  blocks the DC component of the square wave and allows through only the rising and falling edges of the square wave. The transformer T 1  converts the high current, low voltage edge input to the high voltage, low (microcurrent) treatment current output, in the illustrated embodiment. 
     One end of the secondary side of the transformer is connected to the conductive tip  108 . The other end of the secondary coil is connected to a dual diode array D 7 . The diode array acts as the treatment current positive peak detector. Resistor R 26  and capacitor C 11  provide a simple sample and hold function of the detected peak. The peak detector output is buffered by op-amp U 5 . The output of the op-amp U 5  is then sampled by the ADC  593  of the microcontroller  434 . 
     During use, a control loop is formed by the DAC U 6 , peak detector, and the microcontroller  434  ADC  593 . The sensed positive peaks of the treatment current are maintained at a constant level by controlling the DAC U 6  output. As the total resistance decreases, the control loop reduces the DAC U 6  output which reduces the amplitude of the edges being input to the transformer T 1 . The control loop effectively converts the voltage source output of the transformer T 1  to a constant current source, in the illustrated embodiment. In this manner, any uncomfortable surges in current are reduced during treatment. 
       FIG.  6    is a graph  600  of a treatment current (I) vs time (t), according to an embodiment. The treatment current is applied during a treatment mode of the handheld sinus treatment device  102  after the handheld sinus treatment device  102  has identified a treatment location  228 . The treatment current provides relief to sinus discomfort and users. 
     According to an embodiment, the treatment current corresponds to a series of sharp current spikes  650  or peaks. According to an embodiment, successive current spikes  650  alternate in direction such that every other current spike  650  flows in a first direction, while intervening current spikes  650  flow in a second, opposite, direction. 
     According to an embodiment, the current spikes  650  correspond to the rising and falling edges of a square wave voltage signal. In one embodiment, the treatment current is generated by feeding a square wave voltage signal to a transformer, such as the transformer T 1 , via a capacitor, such as the capacitor C 10 . Those of skill in the art will recognize, in light of the present disclosure, that a treatment current in accordance with  FIG.  6    can be generated in various ways. All such other ways for generating the treatment current fall within the scope of the present disclosure. 
     In one embodiment, the treatment current has no DC offset. The lack of a DC offset can enhance the therapeutic effect of the treatment current. This is because, in one interpretation, the rapid changes in current magnitude and direction promote physiological effects that do not occur in the presence of a DC current. 
     In one embodiment, the sinus treatment circuitry  429 , including the microcontroller  434  and the memory  432 , adjust the stimulation voltage between the conductive tip  108  and the return electrode  110  to maintain a constant treatment current during the treatment mode. In one embodiment, maintaining a constant treatment current corresponds to causing the current spikes  650  or peaks of the treatment current to have substantially the same magnitudes. In one embodiment, maintaining a constant treatment current corresponds to causing the current spikes  650  or peaks of the treatment current to have substantially the same absolute values. Thus, the positive current peaks  650  and the negative current peaks  650  have the same absolute value, in one embodiment. Alternatively, maintaining a constant treatment current corresponds to causing the positive current spikes  650  or peaks to have a same first magnitude, and causing the negative current spikes  650  or peaks to have a same second magnitude. 
     In one embodiment, the current spikes  650  or peaks of the sinus treatment current have a magnitude less than or equal to 1000 μA. In one embodiment, the current spikes  650  or peaks of the sinus treatment current have a magnitude less than or equal to 600 μA. In one embodiment, the peaks of the treatment current spikes  650  or peaks have a magnitude less than or equal to 600 μA. In one embodiment, the sinus treatment current spikes  650  have an average current less than or equal to 1000 μA. In one embodiment, the sinus treatment current spikes  650  have an average current less than or equal to 600 μA. 
     In one embodiment, the frequency of the treatment current is less than 1000 Hz. In one embodiment, the period of a single treatment current cycle corresponds to the time between current peaks  650  of the same direction. In one embodiment, the frequency of the treatment current is between 1 Hz and 100 Hz. In one embodiment, the spikes in the treatment current  650  make up less than 10% of a single cycle. In one embodiment, the spikes in the treatment current  650  make up less than 5% of a single cycle. In one embodiment, the spikes in the treatment current  650  make up about 3% of a single cycle. 
     In one embodiment, during the treatment mode, the handheld sinus treatment device  102  measures the impedance by measuring the current spikes  650  or peaks of the treatment current. In one embodiment, the handheld sinus treatment device  102  adjusts a stimulation voltage applied between the conductive tip  108  and the return electrode  110  to bring the magnitude of the current spikes  650  or peaks of the treatment current back to a desired constant value. 
     Those of skill in the art will recognize, in light of the present disclosure, that in practice the treatment current may vary from the graph  600 . For example, the risetime and fall time of a given current spike  650  may not be identical. The rise times and fall times of separate current spikes  650  may not be identical to each other. A given current spike  650  can include, at the tail end, a brief portion that flows in the opposite direction to the primary direction of the current spike  650 . In a constant current situation, the current spikes  650  may have slightly differing magnitudes while remaining substantially the same. There may be noise present among the current waveform. All such variations from the graph  600  fall within the scope of the present disclosure. 
     In one embodiment, in the detection mode in which the handheld sinus treatment device  102  identifies treatment locations  228 , the handheld sinus treatment device  102  measures the impedance by applying a detection current with a waveform similar or identical to the treatment current waveform and measuring the magnitude of the current peaks of the detection current in order to determine the impedance. In one embodiment, the handheld sinus treatment device  102  measures the impedance by passing a detection current with a smaller magnitude than the treatment current. In one embodiment, during the detection mode, the handheld sinus treatment device  102  applies a detection voltage that is lower than the stimulation voltage applied during the treatment mode. In one embodiment, the handheld sinus treatment device  102  measures the impedance by passing a detection current with a waveform entirely different than the treatment current waveform. 
       FIG.  7    is a graph  700  of a treatment current (I) vs time (t), according to an embodiment. Similar to the graph  600  of  FIG.  6   , the treatment current includes a series of current spikes  650 . The treatment current is passed between the conductive tip  108  and the return electrode  110  through the body of the user during the treatment mode of the handheld sinus treatment device  102 . 
     In order to promote the further comfort of the user during the treatment mode, the magnitude of the treatment current is gradually increased during the treatment mode. In particular, at the beginning of the treatment mode, successive current spikes  650  increase in magnitude until the treatment current has arrived at the full treatment level. In this way, during the treatment mode, the user does not immediately receive the full magnitude of the current spikes  650 , but rather the magnitude of the current spikes  650  gradually increased in a comfortable manner to a full treatment level. 
     In one embodiment, a first current spike  650   a  has a magnitude that is much smaller than a full treatment level. A second current spike  650   b  has a magnitude or absolute value that is greater than the magnitude of the first current spike  650   a , though in the opposite direction. A third current spike  650   c  has a magnitude or absolute value that is greater than the second current spike  650   b . A fourth current spike  650   d  has a magnitude or absolute value that is greater than the third current spike  650   c . A fifth current spike  650   e  has a magnitude or absolute value that is greater than the fourth current spike  650   d . A sixth current spike  650   f  has a magnitude or absolute value that is greater than the fifth current spike  650   e . A seventh current spike  650   g  has a magnitude or absolute value that is greater than the sixth current spike  650   f . The magnitude of the seventh current spike  650   g  corresponds to the full treatment level. In one embodiment, all of the successive current spikes  650   h - 650   i  that follow the seventh current spike  650   g  have a same magnitude or absolute value corresponding to the full treatment level. The treatment mode for a given treatment location  228  can include a much larger number of current spikes  650  than are shown in the graph  700  depending on the duration of the treatment mode and the frequency of the treatment current. 
     In one embodiment, the current spikes  650  in a first direction ramp up to a first direction full treatment level, while the current spikes  650  in the second direction ramp up to a second direction full treatment level different than the first direction full treatment level. 
     In one embodiment, after the treatment current has been applied to a treatment location  228  and identified during a treatment mode, the user proceeds to locate the next treatment location  228  during a subsequent detection mode. When the user has located the next treatment location  228 , the handheld sinus treatment device  102  applies a treatment current that ramps up to a full treatment level similar to the previous treatment mode. 
       FIG.  8    is an enlarged view of a portion of the handheld sinus treatment device  102 , according to one embodiment. The conductive tip  108  extends from the housing  106 . The conductive tip  108  includes a distal surface  856  distal from the housing  106 . The conductive tip  108  includes a columnar portion  860  that extends towards distal surface  856 . The distal surface  856  is configured to be placed on the face  226  of the user to detect treatment locations  228  and to apply the treatment current. 
     In one embodiment, the handheld sinus treatment device  102  includes a dielectric covering  852  positioned on the conductive tip  108 . The dielectric covering  852  is positioned on the conductive tip  108  in such a way that a portion of the distal surface  856  is covered by the dielectric covering  852  and a portion of the distal surface  856  is uncovered by the dielectric covering  852 . Thus, according to an embodiment, the dielectric covering  852  defines a covered portion  857  of the distal surface  856  and an exposed portion  854  of the distal surface  856 . The dielectric covering  852  also includes a distal surface  858  distal to the housing  106 . The distal surface  858  can also be considered a top surface of the dielectric covering  852 , according to one embodiment. 
     In one embodiment, the dielectric covering  852  is positioned so that the distal surface  858  of the dielectric covering  852  is in contact with the face  226  of the user when the exposed portion  854  is in contact with the face  226  of the user. Thus, while the user uses the handheld sinus treatment device  102  to detect treatment locations  228  and to apply the treatment current, both the exposed portion  854  of the conductive tip  108  and the distal surface  858  of the dielectric covering  852  are in contact with the face  226  of the user. 
     In one embodiment, it can be beneficial for the treatment current to have a high current density at the treatment location  228  such that the nerve node receives a high current density. In order to promote a high current density at the treatment location  228 , it is beneficial for a relatively small surface area of the conductive tip  108  to contact the user&#39;s face  226  at the treatment location  228 . One way to ensure a relatively small surface area of the conductive tip  108  contacts the user&#39;s face  226  during treatment is to have a conductive tip  108  that is relatively sharp at the point of contact. However, this can promote great discomfort in the user. In some cases, such a sharp conductive tip  108  could scratch, pierce, or otherwise induce pain or damage at the treatment location  228 . 
     In one embodiment, in order to avoid discomfort, the conductive tip  108  includes a distal end  856  that is very gently rounded such that the user does not experience discomfort when placing the conductive tip  108  on the face  226  of the user. As set forth above, without taking other measures, such a gently rounded conductive tip  108  could decrease the current density at the treatment location  228  because the larger surface area of the conductive tip  108  would be in contact with the user&#39;s face  226 . 
     In one embodiment, the presence and configuration of the dielectric covering  852  enhances the comfort of the user while also enabling a relatively high current density at the treatment location  228  or nerve node. In particular, the distal surface  856  is rounded such that the distal surface  856  has a relatively low radius of curvature. Nevertheless, the dielectric covering  852  covers a portion of the distal surface  858  such that during use of the handheld sinus treatment device  102 , only the exposed portion  854  of the distal surface  856  is in contact with the face  226  of the user. The exposed portion  854  is rounded with a low radius of curvature. The distal surface  858  of the dielectric covering  852  will also be in contact with the face  226  of the user during use of the handheld sinus treatment device  102 . Because only an exposed portion  854  of the distal surface  856  is in contact with the face  226  of the user, relatively high current density is maintained during the treatment mode at the treatment location  228 . Because the distal surface  856  is rounded, the user does not experience discomfort when the conductive tip  108  is placed on the face  226  of the user. 
     In  FIG.  8   , portions of the conductive tip  108  that are covered by the dielectric covering  852  and the housing  106  are shown in dashed lines. 
     In one embodiment, the dielectric covering  852  covers a portion of the columnar portion  860  of the conductive tip  108 . In one embodiment, the housing  106  covers a columnar portion  860  of the conductive tip  108 . In one embodiment, the dielectric covering  852  is positioned on and in contact with the housing  106 . In one embodiment, the distal surface  858  of the dielectric covering  852  is rounded to promote comfort for the user while using the handheld sinus treatment device  102 . 
     In one embodiment, the conductive tip  108  includes a material that is electrically conductive while having a lower thermal conductivity than traditional electrical conductors such as copper, gold, silver, iron, aluminum, titanium, and other common metal alloys that are electrically conductive. Such traditional conductive materials also have relatively high thermal conductivities. Such high thermal conductivity can cause discomfort when the material is placed on the skin of the user. If a material with high thermal conductivity is relatively cold compared to the skin of the user, the material will feel colder than would a material with lower thermal conductivity but at the same temperature as the material with higher thermal conductivity. Likewise, if a material high thermal conductivity is relatively hot compared to the skin of the user, the material will feel hotter on the skin of the user than would a material with lower thermal conductivity without the same temperature as the material of higher thermal conductivity. Accordingly, in one embodiment, the conductive tip  108  includes a material that is both electrically conductive while having a relatively low thermal conductivity with respect to traditional conductors. 
     In one embodiment, the conductive tip  108  includes a conductive polymer. The conductive polymer has a low thermal conductivity compared to typical electrical conductors. The conductive polymer is also electrically conductive such that the treatment current can be applied between the conductive tip  108  and the return electrode  110 . In one embodiment, the conductive polymer includes one or more of polyacetylene, polyethylene vinylene, polypyrrole, polythiophene, polyaniline, and polyphenylene sulfide. Those of skill in the art will recognize, in light of the present disclosure, that the conductive tip  108  can include other materials that are electrical conductors with relatively low thermal conductivity. All such other materials fall within the scope of the present disclosure. 
     In one embodiment, the dielectric covering  852  includes a plastic material. In one embodiment, the dielectric covering  852  includes a ceramic material. In one embodiment, the dielectric covering  852  includes an epoxy material. In one embodiment, the dielectric covering  852  includes a rubber material. 
     In one embodiment, the conductive tip  108  includes an electrical conductor including one or more of aluminum, titanium, gold, silver, iron, or other conductive metals, metal alloys, or other kinds of conductive materials. 
       FIG.  9 A  is an illustration of a portion of a handheld sinus treatment device  102  including a resilient member  966 , according to one embodiment. The resilient member  966  is coupled to the conductive tip  108  and the housing  106  in such a way that the conductive tip  108  resiliently depresses toward the housing  106  when pressure or force is applied to the conductive tip  108 . When the pressure or force is no longer applied to the conductive tip  108 , the resilient member  966  returns to an equilibrium position, thereby causing the conductive tip  108  return to the equilibrium position. 
     In some cases, if a user accidentally presses the conductive tip  108  against the skin of the user with too much force, the user could feel discomfort at that location if the conductive tip  108  is rigidly positioned relative to the housing  106 . Accordingly, in order to further enhance the comfort of the user, the handheld sinus treatment device  102  includes the resilient member  966  coupled to the conductive tip  108  in the housing  106 . When the user presses the conductive tip  108  against the skin of the user, the resilient member  966  flexes in a way that enables the conductive tip  108  to depress toward the housing  106 . Thus, if the user accidentally applies a larger than normal amount of force when pressing the conductive tip  108  against the skin, the user will not experience discomfort because the conductive tip  108  will depress downward due to the coupling with the resilient member  966 . 
     In one embodiment, the resilient member  966  is positioned within the housing  106 . The resilient member  966  is in contact with a portion of the conductive tip  108  that is also positioned within the housing  106 . The resilient member  966  is coupled to the conductive tip  108  and configured to enable the conductive tip  108  to resiliently depress toward the housing  106 . Because a portion of the conductive tip  108  may be positioned within the housing  106 , depression of the conductive tip  108  toward the housing  106  can correspond to a distal surface  856  or treatment surface of the conductive tip  108  the pressing toward the housing  106 . 
     In one embodiment, the resilient member  966  is positioned external to the housing  106 . For example, the resilient member  966  can be positioned on an upper surface of the housing  106  between the housing  106  and the conductive tip  108 . In this case, electrical connections to the conductive tip  108  may couple to the conductive tip  108  external to the housing  106 . Because the entirety of the conductive tip  108  may be positioned external to the housing  106 , depression of the conductive tip  108  toward the housing  106  can correspond to depression of the entire conductive tip  108  toward the housing  106 . 
     In one embodiment, the resilient member  966  includes a spring. When pressure is applied to the conductive tip  108 , the pressure causes the spring to compress such that the conductive tip  108  depresses or moves toward the housing  106 . When the pressure is no longer applied to the conductive tip  108 , the spring decompresses and the conductive tip  108  extends from the housing  106  to a rest position. 
     In one embodiment, the resilient member  966  includes a flexible membrane. When pressure is applied to the conductive tip  108 , the pressure causes the flexible membrane to deform in a direction away from the face  226  of the user. The conductive tip  108  in turn depresses toward the housing  106 . When the pressure is no longer applied to the conductive tip  108 , the flexible membrane returns to an equilibrium position and the conductive tip  108  extends from the housing  106  toward an equilibrium position. 
     In one embodiment, the resilient member  966  includes an elastic material. In one embodiment, the resilient member  966  includes rubber. Other resilient materials, configurations, and structures can be selected for the resilient member  966  without departing from the scope of the present disclosure. 
       FIGS.  9 B and  9 C  are illustrations of a portion of handheld sinus treatment device  102  including a spring  968 , according to one embodiment. The spring  968  is coupled to the housing  106  and the conductive tip  108  in such a way that enables the conductive tip  108  to depress toward the housing  106  when pressure or force is applied to the conductive tip  108 .  FIG.  9 A  is an illustration of the handheld sinus treatment device  102  in a condition in which external force or pressure is not applied to the conductive tip  108 , such that the conductive tip  108  and the spring  968  are in equilibrium position.  FIG.  9 B  is an illustration of the handheld sinus treatment device  102  in a condition in which external force or pressure is applied to the conductive tip  108 , such that the spring  968  is compressed and the conductive tip  108  has depressed toward the housing  106 . 
     In one embodiment, the spring  968  is positioned internally within the housing  106 . Alternatively, the spring  968  can be positioned external to the housing  106 . For example, the spring  968  can be positioned on a top surface of the housing  106  between the housing  106  and the conductive tip  108 . 
     In one embodiment, the spring  968  is an electrical conductor. The spring  968  can electrically couple the conductive tip  108  sinus treatment circuitry positioned within the housing  106  such that when the treatment current passes through the conductive tip  108 , the treatment current also passes through the spring  968 . 
       FIGS.  9 D and  9 E  are illustrations of a portion of handheld sinus treatment device  102  including a flexible membrane  970 , according to one embodiment. The flexible membrane  970  is coupled to the housing  106  and the conductive tip  108  in such a way that enables the conductive tip  108  to depress toward the housing  106  when pressure or force is applied to the conductive tip  108 .  FIG.  9 D  is an illustration of the handheld sinus treatment device  102  in a condition in which external force or pressure is not applied to the conductive tip  108 , such that the conductive tip  108  and the flexible membrane  970  are in equilibrium position.  FIG.  9 E  is an illustration of the handheld sinus treatment device  102  in a condition in which external force or pressure is applied to the conductive tip  108 , such that the flexible membrane  970  is deformed and the conductive tip  108  has depressed toward the housing  106 . 
     In one embodiment, the flexible membrane  970  is positioned internally within the housing  106 . Alternatively, the flexible membrane  970  can be positioned external to the housing  106 . For example, the flexible membrane  970  can be positioned on a top surface of the housing  106  between the housing  106  and the conductive tip  108 . 
     In one embodiment, the flexible membrane  970  is an electrical conductor. The flexible membrane  970  can electrically couple the conductive tip  108  sinus treatment circuitry positioned within the housing  106  such that when the treatment current passes through the conductive tip  108 , the treatment current also passes through the flexible membrane  970 . 
       FIG.  10    is a flow chart illustrating a process  1000  of operating a sinus treatment device, according to an embodiment of the disclosure. 
     At  1002 , an impedance is detected between a conductive tip and a return electrode of a sinus treatment device, according to one embodiment. 
     At  1004 , a treatment mode of the sinus treatment device is initiated by passing a treatment current between the conductive tip and the return electrode, according to one embodiment. 
     At  1006 , a magnitude of the treatment current is gradually increased during the treatment mode, according to one embodiment. 
       FIG.  11    is a flow chart illustrating a process  1100  of operating a sinus treatment device, according to an embodiment of the disclosure. 
     At  1102 , an impedance is detected between a conductive tip and a return electrode of a sinus treatment device, according to one embodiment. 
     At  1104 , a treatment mode of the sinus treatment device is initiated responsive to the impedance, according to one embodiment. 
     At  1106 , a treatment current including a series of current spikes is passed between the conductive tip and the return electrode during the treatment mode, according to one embodiment. 
     At  1108 , a magnitude of the current spikes is gradually increased during the treatment mode until the magnitude reaches a full treatment level, according to one embodiment. 
     In one embodiment, an initial stimulation voltage of the treatment mode driven across the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ) is a user selected stimulation voltage received from a user input of the handheld sinus treatment device (e.g.,  102 ). 
     In one embodiment, a method includes initiating a haptic feedback of the handheld sinus treatment device (e.g.,  102 ) when the treatment mode is initiated. 
     In one embodiment, a method includes illuminating a light emitting diode of the handheld sinus treatment device (e.g.,  102 ) when the treatment mode is initiated. 
     In one embodiment, the return electrode (e.g.,  110 ) is attached to a body (e.g.,  106 ) of the handheld sinus treatment device (e.g.,  102 ) that is formed to be held by a hand of a user of the handheld sinus treatment device (e.g.,  102 ) and the return electrode (e.g.,  110 ) is exposed to contact the hand of the user. In one embodiment, the return electrode (e.g.,  110 ) is included in a body (e.g.,  106 ) of the handheld sinus treatment device (e.g.,  102 ), and wherein the body (e.g.,  106 ) includes conductive polycarbonate to serve as the return electrode (e.g.,  110 ). 
     In one embodiment, the process  1100  further includes turning off the handheld sinus treatment device (e.g.,  102 ) when the impedance between the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ) is over a pre-determined threshold for a pre-determined time period (e.g., 2 minutes). 
     In one embodiment of the process  1100 , driving the stimulation voltage across the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ) includes driving voltage pulses across the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ). 
     In one embodiment, the conductive tip (e.g.,  108 ) is a spring-loaded tip to reduce the pressure of the conductive tip (e.g.,  108 ) on a sinus skin area of the user of the handheld sinus treatment device (e.g.,  102 ). In one embodiment, the conductive tip (e.g.,  108 ) includes a conductor and a dielectric tip and both the conductor and the dielectric tip contact a sinus skin area of the user when the conductive tip (e.g.,  108 ) is applied to the sinus skin area of the user. In one embodiment, the conductor includes carbon fiber. 
     In one embodiment, a method of operating a handheld sinus treatment device (e.g.,  102 ) includes measuring a stimulation signal from a conductive tip (e.g.,  108 ) of the handheld sinus treatment device (e.g.,  102 ) where the stimulation signal is representative of a treatment current between the conductive tip (e.g.,  108 ) and a return electrode (e.g.,  110 ) attached with a body (e.g.,  106 ) of the handheld sinus treatment device (e.g.,  102 ). The process further includes dynamically adjusting a stimulation voltage across the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ) to keep the treatment current at a constant value in response to measuring the stimulation signal. 
     According to an embodiment, a method of operating a handheld sinus treatment device (e.g.,  102 ) includes detecting an impedance between a conductive tip (e.g.,  108 ) of the handheld sinus treatment device (e.g.,  102 ) and a return electrode (e.g.,  110 ) of the handheld sinus treatment device (e.g.,  102 ). The method includes initiating a treatment mode of the handheld sinus treatment device (e.g.,  102 ) when the impedance drops below a threshold by applying a stimulation voltage between the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ). The method includes changing the stimulation voltage as the impedance between the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ) changes during the treatment mode. 
     According to an embodiment, a method includes applying, with a handheld sinus treatment device (e.g.,  102 ), sinus treatment stimulation to a sinus treatment location (e.g.,  228 ) of a user by applying a treatment current between a conductive tip (e.g.,  108 ) and a return electrode (e.g.,  110 ) of the handheld sinus treatment device (e.g.,  102 ). The method includes measuring a stimulation signal representative of the treatment current and maintaining a constant value of the treatment current during the treatment mode by dynamically adjusting a stimulation voltage between the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ) in response to measuring the stimulation signal. 
     According to an embodiment, a method of operating a handheld sinus treatment device (e.g.,  102 ) includes initiating a treatment mode of the handheld sinus treatment device (e.g.,  102 ) by applying a stimulation voltage between a conductive tip (e.g.,  108 ) of a handheld sinus treatment device (e.g.,  102 ) and a return electrode (e.g.,  110 ) of the handheld sinus treatment device (e.g.,  102 ). The method includes changing the stimulation voltage as an impedance between the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ) changes during the treatment mode. 
     According to an embodiment, a handheld sinus treatment device (e.g.,  102 ) includes a conductive tip (e.g.,  108 ), a return electrode (e.g.,  110 ) operatively coupled to a body (e.g.,  106 ) of the handheld sinus treatment device (e.g.,  102 ), and a stimulation driver stage coupled to apply a stimulation voltage between the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ). The handheld sinus treatment device (e.g.,  102 ) includes a peak detector coupled to generate a peak treatment current signal in response to receiving a stimulation signal from the conductive tip (e.g.,  108 ). The handheld sinus treatment device (e.g.,  102 ) includes a microcontroller (e.g.,  434 ) coupled to receive the peak treatment current signal from the peak detector and coupled to the stimulation driver stage for adjusting the stimulation voltage in response to the peak treatment current signal. The microcontroller (e.g.,  434 ) dynamically adjusts the stimulation voltage to keep the peak treatment current signal at a constant value. 
     According to an embodiment, a handheld sinus treatment device (e.g.,  102 ) includes a body (e.g.,  106 ) configured to be held in a hand of user, a conductive tip (e.g.,  108 ) coupled to the body (e.g.,  106 ), and a return electrode (e.g.,  110 ) positioned on the body (e.g.,  106 ) such that when a user holds the body (e.g.,  106 ) the hand of the user is in contact with the return electrode (e.g.,  110 ). The handheld sinus treatment device (e.g.,  102 ) includes sinus treatment circuitry positioned within the body (e.g.,  106 ) and configured to detect an impedance between the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ) and to enter a treatment mode responsive to the impedance dropping below a threshold by applying a treatment current between the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ). 
     According to an embodiment, a method includes detecting, during a detection mode, an impedance between a conductive tip (e.g.,  108 ) of a sinus treatment device (e.g.,  102 ) and a return electrode (e.g.,  110 ) of the sinus treatment device (e.g.,  102 ). The method includes initiating a treatment mode of the sinus treatment device (e.g.,  102 ) when the impedance drops below a threshold including passing a treatment current between the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ). The treatment current includes a series of current spikes (e.g.,  650 ). 
     According to an embodiment, a method includes detecting, during a detection mode, an impedance between a conductive tip (e.g.,  108 ) of the sinus treatment device (e.g.,  102 ) and a return electrode (e.g.,  110 ) of the sinus treatment device (e.g.,  102 ). The method includes initiating a treatment mode of the sinus treatment device (e.g.,  102 ) when the impedance drops below a threshold including passing a treatment current between the conductive tip (e.g.,  108 ) and the return electrode (e.g.,  110 ). The treatment current has a magnitude less than 1000 μA. 
     The processes explained above are described in terms of computer software and hardware. The techniques described may constitute machine-executable instructions embodied within a tangible or non-transitory machine (e.g., computer) readable storage medium, that when executed by a machine will cause the machine to perform the operations described. Additionally, the processes may be embodied within hardware, such as an application specific integrated circuit (“ASIC”) or otherwise. 
     A tangible non-transitory machine-readable storage medium includes any mechanism that provides (i.e., stores) information in a form accessible by a machine (e.g., a computer, network device, personal digital assistant, manufacturing tool, any device with a set of one or more processors, etc.). For example, a machine-readable storage medium includes recordable/non-recordable media (e.g., read only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, etc.). 
       FIG.  12    shows several views of a microcurrent sinus treatment device  1200 , according to an embodiment. 
     The inventors note that the device described herein includes several features intended to provide a positive user experience. 
     With respect to structure, a therapeutic tip may include a screw thread to hold a case together with no external screws. 
     According to an embodiment, a device includes a metal or metal-coated plastic return electrode on a case structure portion that occupies an area selected to make it nearly impossible for a user to hold the device without completing a circuit. In an embodiment, the device uses metal-plated plastic. In an embodiment, the device uses punched aluminum for the exposed portion of the return electrode. 
     Referring to  FIG.  12   , according to an embodiment, a microcurrent sinus treatment device  1200  includes a circuit configured to deliver a sequence of voltage pulses carrying a therapeutic current, and a therapeutic electrode  1204  operatively coupled to the circuit. In an embodiment, the therapeutic electrode  1204  may be configured to apply the sequence of voltage pulses to a user&#39;s skin surface adjacent to one of a plurality of nerve nodes subjacent to the user&#39;s skin surface. In an embodiment, the therapeutic electrode  1204  may be in electrical continuity with a therapeutic current output node of the circuit. According to an embodiment, the microcurrent sinus treatment device  1200  includes a hand holdable case  1206  configured to substantially contain active portions of the circuit. In an embodiment, the hand holdable case  1206  includes a forward end  1208  terminating in the therapeutic electrode  1204 , and a return electrode  1210  comprising a portion of or disposed on a surface of the hand holdable case  1206 . In an embodiment, the return electrode  1210  may be in electrical continuity with a current return node of the circuit. In an embodiment, the hand holdable case  1206  includes a dielectric spacer  1212  disposed between the therapeutic electrode  1204  and the return electrode  1210 , and a rearward portion  1214  of the hand holdable case  1206  terminating at an end  1220  a distance selected to comfortably fit in an adult human hand, typically less than about four inches from the therapeutic electrode  1204  tip. In an embodiment, the dielectric spacer  1212  and the return electrode  1210  form a tapered surface  1216  narrowing toward the therapeutic electrode  1204  from a point of maximum girth disposed between the forward end  1208  and the rearward end  1220  of the hand holdable case  1206 . 
     According to an embodiment, the therapeutic electrode  1204  is configured to clamp the return electrode  1210  against the rearward portion  1214  of the hand holdable case  1206  to hold the dielectric spacer  1212  and the return electrode  1210  together with the rearward portion  1214  of the hand holdable case  1206 . In an embodiment, the therapeutic electrode  1204  includes a threaded portion configured to screw into a hole (not shown) formed inside the rearward portion  1214  of the hand holdable case  1206 . In another embodiment, the placement of the therapeutic electrode  1204 , the dielectric spacer  1212 , and the return electrode  1210  are configured to cause the user&#39;s body to complete a circuit between the therapeutic electrode  1204  and the return electrode  1210 . 
     In an embodiment, the tapered case is adaptable to a large range of hand sizes. In an embodiment, the rearward end  1220  of the hand holdable case  1206  is less than three inches from the therapeutic electrode  1204  tip. In an embodiment, the tapered surface  1216  is conducive to cause the user&#39;s hand to naturally contact the return electrode  1210 . In an embodiment, the tapered surface  1216  is conducive to provide satisfactory control for holding the therapeutic electrode  1204  against the user&#39;s skin superjacent to each of the plurality of nerve nodes. 
     According to an embodiment, in  FIG.  12   , the hand holdable case  1206  forms a surface having an indentation larger than an average user&#39;s thumb on a back side of the hand holdable case  1206  such that a front portion of the indentation extends toward the therapeutic electrode  1204  and away from the point of maximum girth of the hand holdable case  1206 . In one embodiment, the indentation is disposed with at least a majority of its area between the therapeutic electrode  1204  and the point of maximum girth. In another embodiment, the indentation is disposed partially extending beyond the point of maximum girth toward the rearward end  1220  of the hand holdable case  1206 . 
     According to an embodiment, the dielectric spacer  1212  defines a concave insulated surface near the therapeutic electrode  1204  to make clearance for the user&#39;s cheek and/or nose. 
     According to an embodiment, the hand holdable case  1206  defines a tapered surface on a top, between the point of maximum girth and the forward end  1208 , configured to provide a finger hold. In an embodiment, the tapered surface forms a facet relative to other portions of the top. 
     According to an embodiment, the hand holdable case  1206  defines a convex curved surface, on the top between the point of maximum girth and the rearward end  1220 , configured to fit into a hollow of the user&#39;s palm. 
     According to a embodiment, the hand holdable case  1206  defines a tapered side  1216  to accommodate finger placement. 
     According to an embodiment, the hand holdable case  1206  further comprises a light pipe  1228  disposed between the forward end  1208  and the return electrode  1210 , the light pipe  1228  being configured to output an illumination indicator from a light emitting diode (LED) disposed on the circuit to indicate an operating condition to the user. 
     According to an embodiment, the microcurrent sinus treatment device  1200  further includes a button  1230  configured to cause the circuit to enter a low current, nerve node finding mode, the circuit being further configured to enter a high current therapeutic voltage pulse mode when a nerve node is found and to automatically shut off when a dose of therapeutic voltage pulses have been delivered. 
     According to an embodiment, the therapeutic electrode  1204  may be configured to maximize comfort for the user. This may be accomplished by keeping a diameter and radius of the therapeutic electrode  1204  tip at the forward end  1208  of the case large enough to avoid applying undue pressure against the user&#39;s skin. The inventors have found that maximizing the diameter and radius for comfort should be balanced against localization of current flow across the user&#39;s skin. In an embodiment, the exposed portion of the therapeutic electrode  1204  may have a diameter greater than or equal to 1/16 of an inch (0.0625″) ( 1/32″=0.031″ radius) and less than ¼″ (0.25″) diameter (⅛″=0.125″ radius). In another embodiment, the exposed portion of the therapeutic electrode  1204  may have a diameter greater than or equal to 3/32″ (=0.094″) ( 3/64″=0.047″) and less than or equal to 3/16″ (0.188″) diameter and 3/32″=0.094″ radius. In another embodiment, the exposed portion of the therapeutic electrode  1204  may have a diameter equal to about 5/32″ (0.16″) and 5/64″ (0.078″ radius). Relevant dimensions, according to an embodiment, are shown in  FIG.  5   . 
     According to embodiments, the inventors have noted three primary ways users may hold the device: 
     1. Thumb directed—the user puts his/her thumb in the indentation and points toward the user&#39;s face. The user&#39;s fingers wrap around the hand holdable case  1206 . 
     2. Finger directed—the user places his/her index finger on the tapered surface  1216  and points toward the user&#39;s face. The user&#39;s fingers and thumb wrap around the hand holdable case  1206 . 
     3. Hybrid—the user places his/her thumb on the indentation and places his/her index finger on the side, both thumb and index finger point toward the user&#39;s face. The user&#39;s middle finger stabilizes along the front. (Some users were found to be unable to use this technique.) 
     All three approaches are amenable to right-handed or left-handed use. Users naturally fell into one of the three grips. Features on the hand holdable case  1206  enable one or more of the grips. 
     While various aspects and embodiments have been disclosed herein, other aspects and embodiments are contemplated. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.