Abstract:
An exemplary embodiment provides a hand-held apparatus for treatment of conditions requiring ultra-sonic or vibratory treatment. The apparatus includes a transducer, an electronic tuning circuit and a power source for powering the apparatus. The transducer has a first section axially aligned with the second section. The second section has an outer wall of predetermined thickness surrounding an annular cavity that contains a piezoelectric stack. The electronic tuning circuit is in communication with the piezoelectric stack. The circuit is configured to tune the transducer to a target output frequency. The transducer, electronic tuning circuit and power source are at least partially contained within a common housing that is configured to be grasped by a human hand to administer treatment.

Description:
BACKGROUND 
     1. Technical Field 
     The present technology relates to the field of medical treatments, and more particularly to devices and methods of treatment of the condition that require application of ultra-sonic or vibratory stimulation to nerves or other body tissue, including tinnitus, Bell&#39;s Palsy, and the like. 
     2. Description of the Related Art 
     Tinnitus is a medical condition in which the afflicted person hears a persistent ringing in one or both ears. The condition may be caused by a number of factors including but not limited to damage to the inner ear, prolonged exposure to noise, the use of certain prescription medications that have ototoxic side effects, ear infections, and nerve-related conditions. The effects of persistent tinnitus may include irritability, fatigue and depression. Tinnitus treatments vary but it has been suggested that in some cases the condition may be ameliorated by application of a noise signal that masks the tinnitus sound effect. Of course, this is not a “treatment” in the sense of ameliorating or curing the condition but merely application of another sound to “cover up” or mask the tinnitus “sound.” 
     Sound may be regarded as a travelling wave in a medium (e.g. air) that exerts pressure on an object in its path (e.g. ear drum of a listener). Travelling waves may be set up by a variety of actions (e.g. clapping hands), mechanical equipment, natural forces (e.g. wind, rain, and thunder) and instruments (e.g. piano). Among the electro-mechanical devices that may be used to generate sound waves in a range of frequencies are transducers. These devices utilize piezoelectric elements that convert an electrical impulse to an applied pressure. Langevin transducers are well-known in the art. These transducers are often used in high frequency sonar and ultra-sonic applications. Langevin transducers most typically include three axially-aligned components: a fore section, an aft section and an axial bolt of high tensile steel that mechanically fastens and pulls the two sections together. Disk-shaped annular piezoelectric elements are located between the fore and aft sections, so that tightening the bolt, which extends though the central hole of the disks, pulls the fore and aft sections together thereby exerting compressive force on the piezoelectric elements sandwiched between the two sections causing them to activate. Other transducer designs may lack a bolt and their sections may be threaded together. 
     SUMMARY 
     An exemplary embodiment provides a hand-held apparatus for treatment of conditions requiring ultra-sonic or vibratory treatment. The apparatus includes a transducer, an electronic tuning circuit and a power source for powering the apparatus. The transducer has a first section and a second section axially aligned with the first section and directly mechanically coupled to the first section, without intervening structures. The second section has an outer wall of predetermined thickness surrounding an annular cavity that contains a piezoelectric stack. The electronic tuning circuit is in communication with the piezoelectric stack and is configured to tune the transducer to a target output frequency. The transducer, electronic tuning circuit and power source are at least partially contained within a common housing that is configured to be grasped by a human hand to administer treatment. 
     In another exemplary embodiment, there is provided a hand-held apparatus for self-administered treatment of a condition requiring ultra-sonic or vibratory stimulation. The apparatus has a common housing that contains a transducer, an electronic tuning circuit and a power source. The transducer has a first section having a central axis. It also has a second, substantially cylindrical, section having a surrounding outer wall defining a cavity containing a piezoelectric stack. The first and second sections are directly mechanically coupled together and may be aligned along a common axis. Moreover, the first and second sections are comprised of the same high strength metallic alloy. The electronic tuning circuit is in communication with the piezoelectric stack and is configured to tune the transducer to a frequency at which the power to the transducer peaks (i.e. the “transducer peak power”). The electronic tuning circuit includes a micro controller, drive electronics and a feedback circuit. 
     An exemplary micro controller applies a control signal to the drive electronics of the transducer which, in response, applies a drive signal to the transducer to operate the transducer at a target frequency. To determine the target frequency, the feedback circuit initially runs a frequency sweep in a range around a nominal frequency that corresponds to a region in which it is known that the transducer will be at peak power. This permits the circuit to select a window of frequency (e.g., about 10 to about 20 Hz) around the tuning point where the power peaks. This tuning point is then set as the target frequency and is communicated to and stored in the drive electronics. Thereafter, to maintain the frequency at the target (or “tuning”) frequency, the feedback circuit interrogates and receives a first feedback signal from the transducer indicating the actual transducer frequency. Responsive to an error between an actual measured transducer frequency and the target frequency, the feedback circuit applies a corrective error signal to the micro controller. The micro controller, in response, applies a corrective control signal to the drive electronics. An electrical connector may be in communication with the micro controller to permit communication there through between the micro controller and an outside electronic device, such as a computer for programming the micro controller or debugging the device. 
     An exemplary micro controller may also be configured or programmed to set the number of doses in a time period and the dose time period (e.g. 60 seconds). It may also be configured or programmed to prevent over-use of the treatment device to exceed the treatment protocol, such as either the maximum dose (in seconds), and/or the number of doses per time period, such as doses per day (12-hour waking period). Further, in another exemplary embodiment, the treatment device may record the treatment protocol that the patient actually used, and this may be downloaded to another electronic device and/or transmitted to a care giver. Such recording of patient use data may improve patient compliance and provide valuable therapeutic feedback. 
     An exemplary embodiment provides a method of self treatment of a condition requiring ultra-sonic or other vibratory stimulation using a hand-held, portable treatment device. The method includes the step of grasping a housing of the hand-held, portable treatment device in a hand and activating the treatment device such that the device emits a target output frequency. Further, it includes the step of placing an exposed portion of a transducer of the activated tinnitus treatment device in direct contact with body tissue for a therapeutically effective period of time. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an illustrative exemplary embodiment of a hand-held, portable treatment device. 
         FIG. 2  is a block diagram depicting components of an exemplary treatment device. 
         FIG. 3  is an illustration, in exploded view, of an exemplary embodiment of a transducer. 
         FIG. 4  is an illustration of the assembled transducer of  FIG. 3 . 
         FIG. 5  is a cross sectional view through  5 - 5  of  FIG. 4 . 
         FIG. 6  illustrates a cross section through a nose section only, to show more detail, of the exemplary embodiment of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the specification, the term “exemplary embodiment” means an example of an embodiment of the technology. 
     Exemplary embodiments provide a hand-held, portable treatment device and a method of self administration of treatment of a condition requiring ultra-sonic or other vibratory stimulation of body tissue or nerves, such as tinnitus. The device has its own internal power source that may be re-chargeable and is relatively small and light weight so that it can be carried in a handbag or pocket. It is therefore convenient for a person to carry with him/her and use, even outside of the home, for greater compliance with a treatment protocol or to use as required. 
     Effective treatment protocols may be prescribed by appropriate professional personnel, and it is expected that treatment will require application of the treatment device to stimulate the body tissue or nerve for brief periods of time, one or more times per day. For example, in the case of tinnitus, a therapeutically effective treatment may be carried out for about 60 seconds or any time period in the range from about 15 to about 90 seconds, or as prescribed, and may be applied to bony tissue behind the ear to stimulate the auditory nerve by bone conduction of the stimulating signal. The treatment may be repeated, as prescribed, a number of times per day, for example from about one to about 4 times per 12 hour waking period, to obtain beneficial results. The frequency of the applied treatment may be in the range of about 50 KHz +/−5 KHz. 
       FIG. 1  shows an exemplary embodiment of a treatment device  100  that may be held in one hand, and that is self-contained, self-powered, and portable. The device  100  has a housing  110  of light-weight material, such as a polymeric material or a polymeric composite, an external switch  700 , and an LED light  740  to indicate when it is activated. A front face  250  of a nose of a transducer  200  (internal, not shown) extends from one end of the device to facilitate its placement behind the ear to initiate treatment. 
       FIG. 2  is a block diagram of an exemplary embodiment indicating electronic components that may be incorporated into a treatment device  100 . Of course, some of these electronic components need not be separate as shown in this example, but may be combined into a single more complex component. The treatment device  100  includes a transducer  200  electrically connected to drive electronics  300 . The transducer  200  is driven at a pre-determined or desired frequency responsive to a drive signal  304  from the drive electronics  300 . The drive electronics  300  is powered by a battery pack or other power source  400 . 
     Exemplary embodiments of a treatment device  100  include a feedback circuit  500  is configured to interrogate the transducer  200  to determine the tuning frequency of the transducer, corresponding to transducer peak power. It is also configured to transmit the determined tuning frequency as a target frequency to the drive electronics  300 . The feedback circuit  500  is also configured to maintain a target frequency, once it is established. The feedback circuit  500  is accordingly configured, for example, to receive a first feedback signal  308  from the transducer  200  indicating the actual transducer frequency. The feedback circuit  500  also receives a second feedback signal  312  from the drive electronics  300  indicating the pre-determined frequency of operation. Responsive to the error between the actual frequency and the pre-determined frequency, the feedback circuit  500  applies an error signal  316  to a micro controller  600 . The micro controller  600 , responsive to the error signal  316 , applies a control signal  320  to the drive electronics  300 . Responsive to the control signal  320 , the drive electronics  300  adjusts the drive signal  304  until the actual transducer frequency more closely approximates the pre-determined or desired frequency throughout the patient treatment cycle. 
     It will be understood by those skilled in the art that the drive electronics, the micro controller and the feedback circuit may be implemented by hardware or by a combination of hardware and software. Also, the feedback circuit  500 , the drive electronics  300  and the micro controller  600  may be implemented as separate elements (e.g. discrete components) as shown in  FIG. 2  or as a single, integrated component. 
     The micro controller  600  is activated by a switch  700  and is in communication with a connector  720 , for example, a USB (universal serial bus) connector or the like. The connector  720  in the illustrated example also receives electrical input energy that is directed to battery charger  730  for recharging a rechargeable battery pack  400 . Of course, the battery pack  400  may also be recharged by other means such as an (external) induction device wherein the treatment device  100  may be placed for recharging. The connector  720  may be used to connect the device  100  to an external computer (not shown in  FIG. 2 ) for programming the micro controller  600  or debugging the device  100 . Further, the treatment device may record the treatment protocol that the patient actually used, and this may also be down loaded. Such recording may improve patient compliance and provide valuable therapeutic feedback. The micro controller  600  can also be programmed to set the number of doses in a time period and the dose time period (e.g. 60 seconds), and to prevent over-use of the treatment device to exceed either the maximum set dose and/or the number of doses per time period, such as per day. The power source  400  powers the micro controller  600 , the feedback circuit  500  and the drive electronics  300 . 
       FIG. 3  illustrates an exemplary embodiment of a transducer  200  that may be used with embodiments of the treatment device  100 . In this illustrated embodiment, the transducer has two main sections: a substantially cylindrical nose section  202  with an annular extension section  204 , and a substantially cylindrical tail section  206 . The two sections are threaded together by threading internal threads  203  of the nose section onto external threading  207  on the front end  215  of the tail section  206 . The annular extension  204  of nose section  202  has an internal cylindrical cavity receiving a stack  220  that is surrounded by an internal dielectric or non-electrically conductive annular sleeve  208  that electrically isolates the stack  220  from the nose section  202 . The stack  220  includes a series of alternating piezoelectric elements  210 , such as rings or disks, and conductive elements  212 , such as copper disks. Thus, when the two sections are threaded together, as shown in  FIGS. 4 and 5 , torque is applied with a tool. This torque application may be facilitated with the aid of optional flats  214  on the nose section  202  and optional tool-engaging machined recesses  216  on the tail section  206 . As a consequence of the applied torque, the stack  220  of the series of alternating piezoelectric elements  210  and the disks  212  is compressed to a desired pressure that activates the piezoelectric stack  220 . 
     The compressive force applied to the stack  220  may be better appreciated with reference to  FIG. 6 . As illustrated in this exemplary embodiment, the nose section  202  has a solid metal cylindrical section  230  from which extends a co-axial machined substantially cylindrical annular extension section  204 . The annular extension section  204  has a first smaller internal diameter portion  234  closer to the solid metal section  230 . The annular extension section  204  extends through portion  234  and has an abrupt internal diameter increase forming a second larger diameter portion  238  with a circumferential internal wall  240  separating the two portions. Thus, when the internal threads  203  of annular extension  204  is threaded to the external threads  207  of tail section  206 , a front end  215  of the tail section  206  will urge up to and abut the wall  240 , which effectively acts as a stop. The front end  215  of tail section  206 , as seen in  FIGS. 3 and 5 , enters into and is threaded to the extension section  204 , thereby exerting compressive force on the stack  220  inside the cavity of the annular extension section  204 . Simultaneously, the applied torque forces apply tensile force to the wall of annular extension section  204 . 
     In exemplary embodiments, the annular extension section, such as annular section  204  depicted in  FIG. 3 , has a wall thickness that stretches in a controlled fashion as torque (and hence tensile forces) is increased. This controlled lengthwise deformation has significance because in exemplary embodiments the overall length of the transducer has an effect on the critical frequency of the standing wave that the transducer generates. Applying torque to thread the sections of the transducer together results in applying compressive force to the piezoelectric stack and tensile force to the wall of the extension section surrounding the stack. Since the amount of compressive force applied to the stack is predetermined, and the overall length of the transducer is also predetermined (by a desired standing wave frequency), the wall thickness of the extension section, and hence its degree of lengthwise expansion under tensile stress, must be controlled to achieve both the desired compressive force on the stack and to maintain the overall transducer length, within close tolerances. 
     An exemplary embodiment of a transducer has all its sections fabricated from a common material, for example, high strength aeronautical grade aluminum alloys, for example AL 7075 and the like. The use of a common material ensures that sound waves (vibrations) are propagated at the same rate (“acoustic velocity”) throughout the device. Moreover, the use of a common material avoids the double wave forms and distorted wave forms that are often encountered with common-place “bolt Langevin transducers.” These transducers have a steel bolt connecting and pulling together two masses, of which one may be steel and the other aluminum, with the piezoelectric stack between under compression. In contrast, exemplary embodiments of useful transducers lack a bolt and produce a wave form with a single peak frequency, which is useful in better controlling the peak frequency and applying uniform treatment to an auditory nerve of a patient. 
     Exemplary embodiments of the tinnitus treatment device include system electronics. An exemplary embodiment may have any one or more of the following features. Frequency generation may be carried out by a dedicated digital signal generator. Moreover, locking to a transducer peak power may be via interrogating with a digitally controlled sweep of transducer frequency, analysis of the sweep data, and modification of the generated digital signal. Power control and level setting are both controllable and may be set in the digital domain. The rechargeable battery may be monitored and charged under firm ware control. The battery may be of the NiMH-type. All aspects of the transducer performance and control may be monitored and stored in memory within the micro controller. Access to this data and reconfiguration of the treatment device may be carried out via the USB connector. 
     While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a wide range of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.