Abstract:
A portable electronic neuromuscular stimulator monitors its battery and estimates battery end of life from the number of charging cycles and usage history. The stimulator can also be used with an external adapter to retrieve internally stored data regarding usage. A simplified user interface allows the user to input a level of pain both before and after treatment.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention is directed to a neuromuscular stimulator and more specifically to one that can monitor its battery to determine remaining battery life, that can be used with an external adapter for retrieval of usage data, and that has a simplified user interface to input a pain level. 
       DESCRIPTION OF RELATED ART 
       [0002]    Neuromuscular stimulators are well known in the art. A battery-powered, portable device is programmed to output pulses through output channels. The channels are connected to electrodes, which the patient places in locations appropriate to the type of muscle stimulation to be applied. The device has a display screen to show a status to the patient and switches to allow the patient to start and, on some devices, select the treatment. 
         [0003]    A typical stimulator is disclosed in U.S. Pat. No. 6,393,328, whose disclosure is hereby incorporated by reference in its entirety into the present disclosure. One exemplary embodiment of the multi-functional electro-medical device in accordance with that patent is programmed to apply interferential current stimulation, high voltage muscle stimulation, and pulsed muscle stimulation treatments. With the ability to provide interferential current stimulation, the multi-functional portable electro-medical device provides the ability to treat painful muscle conditions. The multi-functional portable electro-medical device invention may be programmed to apply many other types of electro-medical treatment such as NEMS, TENS, microcurrent, high voltage, constant voltage or pulse width, and the like. The device also has a removable storage card to store data concerning the operation of the device. The storage card can be given to the physician or mailed to a service bureau. 
         [0004]    The device of the &#39;328 patent will be described in further detail with reference to  FIGS. 1-5  of that patent, which are reproduced herein.  FIGS. 1-4  illustrate an exemplary embodiment of the multi-functional portable electro-medical device  10  of the &#39;328 patent. The multi-functional portable electro-medical device  10  includes a power switch  12 , a liquid crystal display (LCD) touch screen  14  and a speaker  26 . Each of the above-described components, as well as other components to be described later herein, may be housed within a plastic case or shell  24 . 
         [0005]    As shown in  FIGS. 3 and 4 , the case or shell  24  of the exemplary electro-medical device  10  may be formed from an upper piece  24   a  and a lower piece  24   b , in order to more easily manufacture the electro-medical device  10 . Four output jacks  16 - 22  may be provided at the rear of the case of the multi-functional portable electro-medical device  10 . The four output jacks  16 - 22  provide a separate jack for each of the output channels. A jack  28  for connecting the electro-medical device  10  to a battery charger (not shown) may be located on, for example, the rear of the electro-medical device  10 . 
         [0006]    The electro-medical device  10  may be used in a self-administered manner by patients for providing treatments prescribed by physicians and/or other health care providers. A multi-functional portable electro-medical device in accordance with the present invention may be used for any number of muscle treatments including, without limitation: the relaxation of muscle spasms, the prevention or retardation of muscle disuse atrophy, increasing local blood circulation in the legs or other limbs of the patient, reeducating the leg muscles or other muscles of the patient, providing immediate post-surgical stimulation of calf muscles of the patient in order to prevent venous thrombosis, maintaining or increasing the range of motions of the patient&#39;s legs or other limbs, relieving acute pain, the relief and management of chronic pain and for reducing edema and/or inflamation as well as many other treatments. 
         [0007]    In order to connect the output jacks  16 - 22  of the electro-medical device  10  to the patient, a like plurality of cables (not shown) is used to make a connection between one of the output jacks and a standard electrode pad (not shown) which contacts the skin of the patient. For safety purposes, a pin of the cable is inserted into each of the respective jacks  16 - 22  in order to connect an electrode pad to the respective output jack  16 - 22 . 
         [0008]    The exemplary embodiment of the multi-functional portable electro-medical device  10  of the &#39;328 patent is a digital device which provides additional safety features for the user. The electro-medical device  10  provides four isolated channels capable of independently treating four separate muscle groups. Each of the four channels has independent output power stages and transformers in order to provide channel separation. The electro-medical device  10  is battery powered in order to provide portability. The battery power of the exemplary embodiment is provided by an internal 7.2 volt nickel cadmium or nickel metal hydride battery system, which eliminates the need for patients to monitor and replace batteries. The LCD touch screen  14  provides visual feedback and an interface for the user. In addition, the circuitry of the electro-medical device  10  includes a speaker  26  that provides audible reinforcement of keystroke actions. Also, each of the electrically isolated channels has a separate intensity control for independently increasing and decreasing the intensity of that channel. 
         [0009]    The power switch  12 , in addition to powering on the electro-medical device  10 , also serves as an off switch for shutting down the device. The muscle stimulation mode contract time and relax time, treatment time and normal/alternating mode selections have built-in default settings. The inferential mode, continuous/variable mode selection, frequency setting, pad selection, and treatment times also have default settings. However, those default settings are easily modified at the time of use in accordance with the prescription or the user&#39;s physician&#39;s instructions. 
         [0010]    An exemplary embodiment of the electro-medical device  10  of the &#39;328 patent may be provided with a data storage card  30 , the details of which are more fully shown and described in U.S. Pat. No. 5,755,745, which is incorporated by reference herein in its entirety. The structure of the storage card  30  is such that it is designed to be used with and removed by the patient from the electro-medical device  10 , or any other similar type of Class II device which a patient uses in an unsupervised manner, mailed to a service bureau for downloading the stored usage information, and replaced with a new data storage card. Typically, a data storage card such as the data storage card  30  disclosed herein is designed to hold 30-60 days of patient usage information, although more modern stimulators can store up to two years of data. During treatment use by the patient, data is accumulated for the treatment period on the data storage card  30 . 
         [0011]      FIG. 5  is a schematic block diagram of an exemplary embodiment of a multi-functional portable electro-medical device  10  of &#39;328 patent. The exemplary electro-medical device  10 , as previously discussed, is powered by a rechargeable 7.2 volt nickel cadmium or nickel hydride battery system  36 , which is recharged, by a battery charger  38 , which may preferably be powered by standard 110 volt household electric current. As a safety feature, the electro-medical device  10  is designed to be inoperative while the battery system  36  is being charged. A battery monitor circuit  40  is connected between the battery system  36  and the processor  42  to control battery charging. The processor  42  serves to control and monitor all of the functions of the electro-medical device  10 . 
         [0012]    However, the fact that the device is battery-powered means that the battery will eventually reach the end of its useful life and need to be replaced. While the device of the &#39;328 patent has a battery monitor circuit  40 , that battery monitor circuit simply determines the amount of charge needed during a charging operation. 
         [0013]    Also, retrieval of usage data is not convenient. Once the storage card is removed, there must be some way to read it, and not all computers will have compatible card readers. 
         [0014]    Furthermore, known devices do not provide user-friendly ways of allowing a user to select the level of treatment and do not accept inputs to assess the success of the treatment. 
       SUMMARY OF THE INVENTION 
       [0015]    A need therefore exists in the art to improve the above matters. 
         [0016]    It is therefore an object of the invention in at least some embodiments to estimate battery end-of-life time. 
         [0017]    It is another object of the invention in at least some embodiments to provide a more convenient way to retrieve stored usage information. 
         [0018]    It is yet another object of the invention to provide an easy way to let the patient select the level of treatment. 
         [0019]    It is still another object of the invention to collect data from which the effectiveness of the treatment can be assessed. 
         [0020]    To achieve the above and other objects, the present invention in at least one embodiment predicts the battery end of life by using the accumulated data stored in the battery data registers, specifically the age of the battery pack and the number of used charging cycles, and the patient usage data. 
         [0021]    The present invention in at least one other embodiment has a data port for connection to an external adapter. The external adapter can have its own nonvolatile memory or can connect to a conventional memory device such as a USB flash drive. 
         [0022]    The present invention in at least one other embodiment has a simplified interface to allow the user to rate the pain level. If the user does so before the treatment, the level of treatment can be automatically determined accordingly. If the user does so both before and after the treatment, the data can be saved to allow a physician or other party to determine the effectiveness of the treatment. 
         [0023]    The present invention can use any or all features of the stimulator of the &#39;328 patent or of any other stimulator. Also, the battery monitoring technique of the present invention can be used in devices other than neuromuscular stimulators, i.e., any device that utilizes a batter that can be monitored as described above. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    Preferred embodiments of the present invention will be set forth in detail with reference to the drawings, in which: 
           [0025]      FIG. 1  is a perspective view of an exemplary embodiment of a multi-functional portable electro-medical device in accordance with the &#39;328 patent; 
           [0026]      FIG. 2  is a top view of the portable electro-medical device of  FIG. 1 ; 
           [0027]      FIG. 3  is a front elevation view of the portable electro-medical device of  FIG. 1 ; 
           [0028]      FIG. 4  is a rear elevation view of the multi-functional portable electro-medical device of  FIG. 1 ; 
           [0029]      FIG. 5  is a schematic block diagram of an exemplary multi-functional portable electro-medical device in accordance with the &#39;328 patent; 
           [0030]      FIG. 6  is a top view of a stimulator according to any of the preferred embodiments; 
           [0031]      FIG. 7  is a side view of the stimulator of  FIG. 6 ; 
           [0032]      FIG. 8  is a top perspective view of the stimulator of  FIG. 6 ; 
           [0033]      FIG. 9  is a bottom perspective view of the stimulator of  FIG. 6 ; 
           [0034]      FIG. 10  is a flow chart showing calculation triggering in the first preferred embodiment; 
           [0035]      FIG. 11  is a flow chart showing the calculation of the estimated battery end of life in the first preferred embodiment; 
           [0036]      FIG. 12  is a perspective view showing the use of an adapter according to the second preferred embodiment; and 
           [0037]      FIG. 13  is a top view of a stimulator having a user interface according to the third preferred embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0038]    Preferred embodiments of the present invention will be set forth in detail with reference to the drawings, in which like reference numerals refer to like elements or steps throughout. 
         [0039]      FIGS. 6-9  show a top view, a side view, a top perspective view, and a bottom perspective view, respectively, of a stimulator  600  according to the preferred embodiments. The stimulator  600  can incorporate any or all features of the &#39;328 stimulator or any other stimulator. The stimulator  600  includes a display screen  602 , a left function key  604 , a right function key  606 , an on/off/pause key  608 , four intensity keys (one for each channel)  610 , a lithium-ion (or other suitable) battery  612 , and a connector  614 . 
         [0040]    The first preferred embodiment concerns battery monitoring. In order to provide the patient with adequate notice that the main battery is approaching its end of life and requires replacement, the device uses the accumulated data stored in the battery data registers and the patient usage data stored in the device NVRAM to predict when a battery will reach its end of life status. First, the device determines whether the prediction is needed. That determination, called calculation triggering, will be explained with reference to the flow chart of  FIG. 10 . 
         [0041]    At POST (power on self test), the battery registers for the battery age (pack date) and the number of used charging cycles are read (step  1002 ). Predictive calculations begin when the battery age (pack date) is 35 months prior to the RTC (real-time clock) date (step  1004 ) or the used charge cycle count is greater than 260 (step  1006 ). In either of those cases, the device performs the calculation (step  1008 ) in the manner explained below. When the battery age is less than 35 months and the charge cycle count is less than 260, no calculation will be done. Instead, the device will wait until the next POST (step  1010 ) to do the determination again. 
         [0042]    The calculation is performed in the following manner, which will be explained with reference to the flow chart of  FIG. 11 . The following empirical data are used: At 100% intensity, the normal INF depletion time is 100 minutes, while the normal NMES depletion time is 524 minutes 
       DEFINITION OF TERMS 
       [0043]    Average Number of Treatments per Day: The average number of INF treatments per day is determined by adding the number of INF treatment segments within the timeframe of evaluation (which is typically the last 20 days) and dividing the sum by the number of days in that time frame of evaluation. Similarly, the average number of NMES treatments per day is determined by adding the number of NMES treatment segments within the timeframe of evaluation and dividing the sum by the number of days in the time frame of evaluation. 
         [0044]    Average Treatment Times: The average INF treatment time is determined by summing the times of all of the INF treatments and dividing that sum by the number of INF treatments. Similarly, the average NMES time is determined by summing the times of all of the NMES treatments and dividing that sum by the number of NMES treatments. 
         [0045]    Average Intensities: The average INF intensity is determined by summing all of the INF intensity settings within the timeframe and dividing the sum by 4 times the number of INF treatments within the timeframe. Similarly, the average NMES intensity is determined by summing all NMES intensity settings within the timeframe and dividing the sum by 4 times the number of NMES treatments within the timeframe. 
         [0046]    When the calculation is triggered ( FIG. 10 , step  1008 ), the device MCU evaluates the patient usage data from the last 20 days stored in the NVRAM for the following information (refer to the definitions of terms above) ( FIG. 11 , step  1102 ): 
         [0047]    Average INF Intensity 
         [0048]    Average NMES Intensity 
         [0049]    Average Number of Treatments per Day 
         [0050]    Average INF Treatment Time 
         [0051]    Average NMES Treatment Time 
         [0052]    Patient Battery Depletion Cycles Due to Intensity (step  1104 ): For INF treatments, that quantity, referred to as NormINFDepletionTime, is calculated as 100×(100/Average INF Intensity). For NMES treatments, that quantity, referred to as NormNMESDepletionTime, is calculated as 524×(100/Average NMES Intensity). 
         [0053]    Average Run Time per Charging Cycle (step  1106 ): That quantity, referred to as EstimatedTreatments, is calculated from the quantities calculated above as [(NormINFDepletionTime/Average INF Treatment Time)+(NormNMESDepletionTime/Average NMES Treatment Time)]. 
         [0054]    Day to next charging (step  1108 ): That quantity, referred to as DayToNextCharging, is calculated as EstimatedTreatments/Average Number of Treatments per Day. 
         [0055]    Estimated EOL (step  1110 )=(300−Cycle Count)/DayToNextCharging). 
         [0056]    The processor determines whether to give a warning message in the following manner. If the estimated EOL is less than 21 Days (step  1112 ) or the pack date is greater than 35 months before the RTC date, (step  1114 ), the device a “Replace battery” message (step  1116 ) for 10 seconds with the backlight on and sounds the alert beep three times. A patient data record for treatment is written with the timestamp as evidence that the message was displayed to the patient. If the estimated EOL is greater than 20 days and the pack date is &lt;35 months, the normal program is continued (step  1118 ). 
         [0057]    Another embodiment uses an adapter to allow downloading of patient data. That embodiment will be disclosed with reference to  FIG. 12 . As shown in that figure, a stimulator  600  has had its connector  614  removed to reveal a DB-25 (or other suitable) port  1202 . A patient data download adapter  1204  has a DB-25 connector  1206  to connect to the DB-25 port  1202  on the stimulator  600 . The adapter  1204  also has a USB 2.0 (or other suitable) port  1208  to connect to a known USB flash drive  1210 , a known USB cable  1212 , or another USB device. The adapter  1204  also has a non-volatile memory  1214 . The specifics of the DB-25 and USB pin assignments are known in the art and will therefore not be described in detail here. USB has been selected because of the high likelihood of compatibility with existing thumb drives and computers, although any other standard could be used. 
         [0058]    Patient data download adapters are identified using the DB-25 pins labeled DETECT 1  and DETECT 2  set to bx01. The device  600  will then access the memory location named “Transfer Type” within the adapter&#39;s memory  1214 . The “Transfer Type” HEX Data Byte will identify the adapter type according to the following table: 
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE I 
               
               
                   
                   
               
               
                   
                 HEX Data Byte 
                 Adapter Type 
               
               
                   
                   
               
             
             
               
                   
                 00 
                 Not to be used 
               
               
                   
                 01 
                 USB 
               
               
                   
                 02 
                 NVRAM 
               
               
                   
                 03-FF 
                 Reserved for future types 
               
               
                   
                   
               
             
          
         
       
     
         [0059]    Since technology continues to change, the reserved HEX data bytes (03-FF) will be used to identify future adapters to take advantage of the most current technology available. Patient data download will be done in the prescribing physician&#39;s office by the physician, a member of the physician&#39;s staff, a sales representative, or a case manager. The physician will insert a flash drive  1210  into the USB 2.0 port built into the adapter  1204  and turn the device on using the On/Off/Pause key  608 . The device  600  detects the presence of a patient data download adapter  1204  using the DETECT 1  and DETECT 2  pins on the DB-25 connector  1206 , identifies the type as USB using the “Transfer Type” HEX data byte, and begins a routine to download the header information (serial number, etc.) and up to two years of patient data saved on the device. Upon completion of the download, the device  600  will beep using the treatment-completed sound and then turn off. When the flash drive  1210  is removed from the device  600  and inserted into the physician&#39;s PC (not shown), a program provided on a CD or other medium or downloaded from a server on the Internet will retrieve the data from the flash drive  1210  and format it to produce a patient report for the previous period of usage. 
         [0060]    In rare cases, the patient will need to be provided with a special adapter  1218  having a DB-25 connector  1220  mating to the DB-25 connector  1202  of the device  600 . The adapter  1218  will have a self-contained non-volatile memory  1222  of sufficient size to hold the two years of patient data contained in the device memory. The device  600  detects the presence of a patient data download adapter  1218  using the DETECT 1  and DETECT 2  pins on the DB-25 connector, identifies the type as a NVRAM using the “Transfer Type” HEX data byte in the manner described above, and begins a routine to download the header information (serial number, etc.) and up to the two years of patient data saved on the device  600  into the memory  1222  of the adapter  1218 . Upon completion of the download, the device  600  will beep using the treatment-completed sound and then turn off. The patient will then return the adapter  1218  to the company providing the device  600 , where the full two years of patient usage data will be retrieved from the memory  1222  in the adapter  1218  and formatted. 
         [0061]    Alternatively, either the physician or the patient can connect the device  600  to a computer (not shown) via the adapter  1204  and a USB cable  1212  to transfer data to the computer using software provided by the vendor of the device  600  and installed on the computer. In the case of a patient, the patient can be given instructions to connect via the computer to a secure Web site to transfer the information to a remote site. 
         [0062]    A third preferred embodiment, which will be explained with reference to  FIG. 13 , offers a simplified user interface. The stimulator  600 , as noted above, has four up-down keys  610 , one to control each channel, and a display  602 . The device  600  outputs a prompt  1302  for the user to select the level of pain. Using any of the keys  610 , the user can select a pain level from 0 (no pain) to 10 (hurts worst). For the currently selected pain level, the device  600  displays at least one of a text description (“No pain”)  1304  and a graphic depiction (emoticon with appropriate facial expression)  1306 . The display also provides prompts  1308 ,  1310  to skip the step and to select the currently selected pain level, which may be selected with the keys  604  and  606 , respectively. The user can make the selection before and after treatment to select an appropriate level of treatment and to provide an input of the effectiveness of the treatment. In a device combining the second and third preferred embodiment, the “before” and “after” data can be output through the adapter. 
         [0063]    While preferred embodiments of the invention have been set forth above, those skilled in the art who have reviewed the present disclosure will readily appreciate that other embodiments can be realized within the scope of the invention. For example, numerical values and disclosures of specific technologies are illustrative rather than limiting. Also, the various preferred embodiments and their modifications can be used together or separately. Therefore, the present invention should be construed as limited only by the appended claims.