Abstract:
Disclosed is a treatment device for urination disorders, said treatment device being capable of determining whether or not stimulation-applying electrodes are appropriately arranged and whether or not nerves that control urine accumulation and urination are being appropriately stimulated. The disclosed treatment device can therefore provide appropriate treatment for urination disorders. The treatment device is provided with: at least one pair of stimulation-applying electrodes that apply a stimulation signal to the dorsal surface of the sacrum; a stimulation-signal source that supplies the stimulation signal applied by the stimulation-applying electrodes; a stimulation-transmission detection electrode that is disposed near tissue connected to nerves that run near the sacrum or to the sacrum, and that detects a biosignal that arises in response to the stimulation signal; a ground electrode; a measurement unit that measures the biosignal detected by the stimulation-transmission detection electrode; a control unit that controls the application of the stimulation signal by the pair of stimulation-applying electrodes; and a display means that displays the measurement result from the measurement unit.

Description:
TECHNICAL FIELD  
       [0001]    The present invention relates to an urination disorder treatment apparatus for treating an urination disorder. 
       BACKGROUND ART 
       [0002]    A conventional urination disorder treatment apparatus has a configuration in which a pair of stimulus applying electrodes arranged on the back of the sacral bone with a predetermined distance between them supply a stimulus signal from a stimulus signal supply source. The conventional urination disorder treatment apparatus alleviates an urination disorder by stimulating the urinary bladder and the urethra by the stimulus signal through a nerve which passes through the sacral micturition reflex center and controls collection and discharge of urine. 
       CITATION LIST 
     Patent Literature 
       [0003]    PTL 1 
         [0004]    Japanese Patent Application Laid-Open No. 3-26623 
       SUMMARY OF THE INVENTION 
     Technical Problem 
       [0005]    However, the conventional urination disorder treatment apparatus may have a difficulty to perform an appropriate treatment. That is, a pair of stimulus applying electrodes need to be arranged on an appropriate portion on the back of the sacral bone to transmit a stimulus to the nerve which passes through the sacral micturition reflex center and controls collection and discharge of urine. This is because an appropriate stimulus cannot be applied to the urinary bladder and the urethra unless a pair of stimulus applying electrodes are arranged at an appropriate position. However, in the conventional urination disorder treatment apparatus, whether or not the stimulus applying electrodes are arranged at an appropriate position cannot be determined, so that an appropriate treatment may not be performed. 
         [0006]    Therefore, an object of the present invention is to provide a urination disorder treatment apparatus which can perform an appropriate treatment of a urination disorder by determining whether the stimulus applying electrodes are appropriately arranged and whether an appropriate stimulus is applied to the nerve that controls collection and discharge of urine. 
       Solution to Problem 
       [0007]    To achieve the above object, the urination disorder treatment apparatus of the present invention has a configuration described below.
       (1) at least a pair of stimulus applying electrodes which is arranged on a back of a sacral bone of the patient with a predetermined distance between the stimulus applying electrodes and which supplies a stimulus signal to the back of the sacral bone;   (2) a stimulus signal supply source that allows the pair of stimulus applying electrodes to supply a stimulus signal;   (3) a stimulus-response detecting electrode which is arranged near a tissue connected to a nerve that passes through the sacral bone or passes near the sacral bone and which detects a biological signal generated in response to the stimulus signal;   (4) a ground electrode arranged on a given portion of skin of the patient;   (5) a measuring section which is connected to the stimulus-response detecting electrode and the ground electrode and which measures a biological signal detected by the stimulus-response detecting electrode;   (6) a control section which is connected to the measuring section and which controls supply of the stimulus signal supplied from the pair of stimulus applying electrodes on the basis of a measurement result of the measuring section; and   (7) a display means which is connected to the control section and on which the measurement result of the measuring section is displayed.       
 
       Advantageous Effects of Invention 
       [0015]    According to the urination disorder treatment apparatus of the present invention, it is possible to determine whether or not a pair of stimulus applying electrodes transmit an appropriate stimulus to a nerve which passes through the sacral micturition reflex center and controls collection and discharge of urine. Specifically, whether or not an appropriate stimulus is transmitted can be determined by measuring a biological signal generated in response to a stimulus to the back of the sacral bone using a stimulus-response detecting electrode and a measuring section. Thereby, an effective treatment is realized. 
         [0016]    According to the urination disorder treatment apparatus of the present invention, whether or not a pair of stimulus applying electrodes transmit an appropriate stimulus to a nerve which controls collection and discharge of urine can be determined from information displayed on the display means. A therapist (or a patient himself or herself) can apply an appropriate stimulus by changing an arrangement position of a pair of stimulus applying electrodes to an appropriate position on the basis of the information displayed on the display means. 
         [0017]    Further, according to the urination disorder treatment apparatus of the present invention, it is possible to adjust the magnitude of the stimulus signal supplied by a pair of stimulus applying electrodes on the basis of the information displayed on the display means. Thereby, a more appropriate stimulus can be applied. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0018]      FIG. 1  is a side cross-sectional view of a human body to which a urination disorder treatment apparatus is applied; 
           [0019]      FIG. 2  is a rear view of the human body to which the urination disorder treatment apparatus is applied; 
           [0020]      FIG. 3  is a block diagram of an urination disorder treatment apparatus in accordance with Embodiment 1 of the present invention; 
           [0021]      FIG. 4  is a block diagram of an urination disorder treatment apparatus in accordance with Embodiment 2 of the present invention; 
           [0022]      FIG. 5  is a block diagram of a urination disorder treatment apparatus in accordance with Embodiment 3 of the present invention; and 
           [0023]      FIG. 6  is a block diagram of an urination disorder treatment apparatus in accordance with Embodiment 4 of the present invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0024]    First, an outline of a treatment mechanism of an urination disorder by an urination disorder treatment apparatus of the present invention will be described. 
         [0025]      FIG. 1  and  FIG. 2  show a region near sacral bone  3  of human body  2 . Sacral bone  3  has sacral foramens  18 . Sacral foramens  18  have bilaterally symmetrical structure in human body  2 . Pelvic splanchnic nerve  20 , pudendal nerve  22 , and hypogastric nerve  28  are engaged in control of collection and discharge of urine (see  FIG. 1 ). Because these nerves are connected to urine bladder  19  and urethral sphincter muscle  21 . 
         [0026]    Pelvic splanchnic nerve  20  is connected from sacral foramen  18  to urine bladder  19 . Pudendal nerve  22  is connected from sacral foramen  18  to urethral sphincter muscle  21 . A symptom of an urination disorder can be alleviated by applying a stimulus to pelvic splanchnic nerve  20  and pudendal nerve  22 . 
         [0027]    As described later, the urination disorder treatment apparatus of the present invention can apply a stimulus to pelvic splanchnic nerve  20  and pudendal nerve  22  via a pair of stimulus applying electrodes  1   a  and  1   b . The “treatment” by the urination disorder treatment apparatus of the present invention includes alleviating the symptom of the urination disorder. 
         [0028]    As shown in  FIG. 1  and  FIG. 2 , sciatic nerve  23  passes through sacral foramen  18  and divides into common peroneal nerve  26  and tibial nerve  27  in a leg. Thereby, sciatic nerve  23  controls a motion of a distal portion of a leg. 
         [0029]    Sciatic nerves  23  have muscle branches and the muscle branches originating from sciatic nerves  23  connect to tissues (muscles) in left leg  5  and right leg  8  of the human body. For example, the muscle branches originating from sciatic nerves  23  connect to biceps femoris muscle  6  of left leg  5  and biceps femoris muscle  9  of right leg  8  (see  FIG. 3 ) and connect to semitendinosus muscle  30  of left leg  5  and semitendinosus muscle  31  of right leg  8  (see  FIG. 4 ). On the other hand, muscle branches originating from tibial nerve  27  connect to gastrocnemius muscle  24  of left leg  5  and gastrocnemius muscle  25  of right leg  8  (see  FIG. 5 ) and connect to soleus muscle  33  of left leg  5  and soleus muscle  34  of right leg  8  (see  FIG. 6 ). 
         [0030]    As described later, the urination disorder treatment apparatus of the present invention includes stimulus-response detecting electrodes  7   a  and  7   b  and stimulus-response detecting electrodes  10   a  and  10   b  (see  FIG. 3  and the like) for detecting a biological signal generated in response to a stimulus signal supplied by a pair of stimulus applying electrodes  1   a  and  1   b.    
         [0031]    A pair of stimulus-response detecting electrodes  7   a  and  7   b  and a pair of stimulus-response detecting electrodes  10   a  and  10   b  only have to detect the biological signal generated in response to the stimulus signal supplied by a pair of stimulus applying electrodes  1   a  and  1   b , and the arrangements thereof are not limited. For example, stimulus-response detecting electrodes  7   a  and  7   b  and stimulus-response detecting electrodes  10   a  and  10   b  may be arranged on skin near urethral sphincter muscle  21  (see  FIG. 1 ) or skin near a perineal muscle that connect to pudendal nerve  22 . 
         [0032]    However, preferably, stimulus-response detecting electrodes  7   a  and  7   b  and stimulus-response detecting electrodes  10   a  and  10   b  are arranged on skin (on back of leg) near muscle tissues in a leg, which are tissues to which sciatic nerve  23  connects. The tissues to which sciatic nerve  23  connects also mean tissues that connect to a nerve branching from sciatic nerve  23 . The nerve branching from sciatic nerve  23  is, for example, tibial nerve  27 . 
         [0033]    As shown in  FIG. 1  to  FIG. 6 , sacral foramens  18  have a bilaterally symmetrical structure and sciatic nerves  23  and tibial nerves also have bilaterally symmetrical structures. Therefore, a biological signal generated in response to a stimulus signal to a left sacral foramen can be detected by stimulus-response detecting electrodes  7   a  and  7   b  arranged on left leg  5 . On the other hand, a biological signal generated in response to a stimulus signal to a right sacral foramen can be detected by stimulus-response detecting electrodes  10   a  and  10   b  arranged on right leg  8 . 
         [0034]    In other words, when a pair of stimulus-response detecting electrodes  7   a  and  7   b  and a pair of stimulus-response detecting electrodes  10   a  and  10   b  are arranged respectively on skins near muscle tissues in both legs that are tissues connected to sciatic nerves  23 , it is easy to separately detect the biological signals generated in response to each of the stimulus signals of a pair of stimulus applying electrodes  1   a  and  1   b . As a result, as described later, it is easy to determine whether or not each of stimulus applying electrodes  1   a  and  1   b  is appropriately arranged. 
         [0035]    Because of the above reason, it is preferred that stimulus-response detecting electrodes  7   a  and  7   b  and stimulus-response detecting electrodes  10   a  and  10   b  are arranged near muscles in left leg  5  and right leg  8  respectively. 
         [0036]    The biological signal generated in response to each of the stimulus signals of a pair of stimulus applying electrodes  1   a  and  1   b  means, typically, an evoked potential. The evoked potential is a potential response that is evoked by tissue when a certain stimulus is applied to a nerve connected to the tissue (for example, muscle tissue). 
         [0037]    Hereinafter, examples of embodiments of the present invention will be described. In Embodiments 1 to 4 described below, a form in which stimulus-response detecting electrodes  7   a  and  7   b  and stimulus-response detecting electrodes  10   a  and  10   b  are arranged near muscle tissues in the legs to which sciatic nerves  23  are connected will be described with reference to the attached drawings. 
       Embodiment 1  
       [0038]    A urination disorder treatment apparatus according to Embodiment 1 includes a pair of stimulus applying electrodes  1   a  and  1   b , a pair of stimulus-response detecting electrodes  7   a  and  7   b , a pair of stimulus-response detecting electrodes  10   a  and  10   b , ground electrode  32 , stimulus signal supply source  4 , measuring section  15 , control section  16 , display means  17 , and operation section  29  (see  FIG. 3 ). 
         [0039]    As shown in  FIG. 3 , a pair of stimulus applying electrodes  1   a  and  1   b  are arranged on the back of sacral bone  3  symmetrically relative to a central axis (with respect to a central axis) of human body  2  with a predetermined distance in between. The back of the sacral bone means a “surface of the back near the sacral bone”. Stimulus signal supply source  4  is connected to a pair of stimulus applying electrodes  1   a  and  1   b.    
         [0040]    As shown in  FIG. 3 , stimulus-response detecting electrodes  7   a  and  7   b  are arranged on the back of biceps femoris muscle  6  of left leg  5 , and stimulus-response detecting electrodes  10   a  and  10   b  are arranged on the back of biceps femoris muscle  9  of right leg  8 . An arrangement distance between stimulus-response detecting electrodes  7   a  and  7   b  and an arrangement distance between stimulus-response detecting electrodes  10   a  and  10   b  are desired to be set in a range of about 2 to 3 cm. 
         [0041]    “Biceps femoris muscle  6 ” in the present description and the claims includes meanings of short head of biceps femoris muscle  11  and long head of biceps femoris muscle  12 . Similarly, “biceps femoris muscle  9 ” includes meanings of short head of biceps femoris muscle  13  and long head of biceps femoris muscle  14 . 
         [0042]    Measuring section  15  is connected to stimulus-response detecting electrodes  7   a  and  7   b  arranged on biceps femoris muscle  6  and stimulus-response detecting electrodes  10   a  and  10   b  arranged on biceps femoris muscle  9 . 
         [0043]    Ground electrode  32  is arranged on a given skin surface and connected to measuring section  15 . Control section  16  is connected to measuring section  15 . Stimulus signal supply source  4 , display means  17 , and operation section  29  are connected to control section  16 . Measuring section  15  is connected to stimulus-response detecting electrodes  7   a  and  7   b , stimulus-response detecting electrodes  10   a  and  10   b , and ground electrode  32 . 
         [0044]    Ground electrode  32  can be arranged on any portion of the skin surface. However, a preferred arrangement position of ground electrode  32  is between a pair of stimulus applying electrodes  1   a  and  1   b  and a pair of stimulus-response detecting electrodes  7   a  and  7   b , or between a pair of stimulus applying electrodes  1   a  and  1   b  and a pair of stimulus-response detecting electrodes  10   a  and  10   b.    
         [0045]    It is preferred that ground electrode  32  is arranged at a position that is not affected by noise caused by muscle action. Although ground electrode  32  shown in  FIG. 3  is one electrode having a flat plate shape, two ground electrodes may be symmetrically arranged on left leg  5  and right leg  8  respectively. Ground electrode  32  may have a shape that is wrapped around the trunk of the body or a leg. 
         [0046]    A pair of stimulus applying electrodes  1   a  and  1   b  can apply a pulse signal of bipolar square wave to the back of sacral bone  3  as a stimulus signal. Stimulus signal supply source  4  is connected to a pair of stimulus applying electrodes  1   a  and  1   b  as a supply source of the pulse signal. The stimulus signal (pulse signal) supplied by a pair of stimulus applying electrodes  1   a  and  1   b  stimulates a nerve which passes through the micturition reflex center located in sacral bone  3  and controls collection and discharge of urine, so that a urination disorder is alleviated. Although, as described above, examples of the nerve which passes through the micturition reflex center and controls collection and discharge of urine include pelvic splanchnic nerve  20 , pudendal nerve  22 , and hypogastric nerve  28 , preferably, the nerve is pelvic splanchnic nerve  20  and pudendal nerve  22  that pass near the sacral bone. 
         [0047]    The voltage of the pulse signal of bipolar square wave, which is a stimulus signal that is supplied from the supply source of stimulus signal supply source  4  and supplied by a pair of stimulus applying electrodes  1   a  and  1   b , can be varied in a range greater than 0 V and smaller than or equal to 80 V. The voltage is set to a maximum value within a range in which patient does not feel pain. The pulse signal of bipolar square wave that is set in this manner has, for example, a pulse width of 200 μs, a frequency of 30 Hz, intermittent timing of 5 seconds of ON and 5 seconds of OFF, and a current of 0 to 80 mA, 
         [0048]    The magnitude of the stimulus signal that is supplied from stimulus signal supply source  4  and applied by a pair of stimulus applying electrodes  1   a  and  1   b  may be adjusted by control section  16  according to an operation on operation section  29 . A therapist (or a patient himself or herself) can operate operation section  29  to set the magnitude of the stimulus signal to an optimal value. Specifically, the therapist can adjust a bipolar square wave voltage of the stimulus signal applied to a pair of stimulus applying electrodes  1   a  and  1   b  in a range greater than 0 V and smaller than or equal to 80 V. 
         [0049]    In this way, the urination disorder treatment apparatus of Embodiment 1 stimulates the nerve that controls collection and discharge of urine via a pair of stimulus applying electrodes  1   a  and  1   b , so that the function of collecting urine is facilitated, and urinary incontinence and frequent urination are prevented. However, if a pair of stimulus applying electrodes  1   a  and  1   b  are not arranged at appropriate positions on the back of sacral bone  3  of human body  2 , it is impossible to appropriately stimulate the nerve, so that a sufficient treatment effect cannot be obtained. 
         [0050]    Therefore, the urination disorder treatment apparatus of Embodiment 1 includes stimulus-response detecting electrodes  7   a  and  7   b  to be arranged on the back of biceps femoris muscle  6  of left leg  5 , and stimulus-response detecting electrodes  10   a  and  10   b  to be arranged on the back of biceps femoris muscle  9  of right leg  8 . 
         [0051]    The urination disorder treatment apparatus of Embodiment 1 can measure a potential difference between stimulus-response detecting electrodes  7   a  and  7   b  and a potential difference between stimulus-response detecting electrodes  10   a  and  10   b . Specifically, measuring section  15  measures the potential difference between stimulus-response detecting electrodes  7   a  and  7   b  and the potential difference between stimulus-response detecting electrodes  10   a  and  10   b  on the basis of the potential of ground electrode  32 . In other words, measuring section  15  can measure a muscle action potential of biceps femoris muscle  6  of left leg  5  detected by stimulus-response detecting electrodes  7   a  and  7   b  and a muscle action potential of biceps femoris muscle  9  of right leg  8  detected, by stimulus-response detecting electrodes  10   a  and  10   b.    
         [0052]    On the other hand, when a pair of stimulus applying electrodes  1   a  and  1   b  stimulate nerves, muscle actions of biceps femoris muscles  6  and  9  are evoked. The feature of the urination disorder treatment apparatus of Embodiment 1 is that the evoked muscle action potentials (referred to as “evoked potentials”) of biceps femoris muscles  6  and  9  are detected by stimulus-response detecting electrodes  7   a  and  7   b  and stimulus-response detecting electrodes  10   a  and  10   b  as a biological signal and the biological signal is measured by measuring section  15 . 
         [0053]    The evoked potentials, which are biological signals, are detected by stimulus-response detecting electrodes after 10 ms to 30 ms has elapsed from when a pair of stimulus applying electrodes  1   a  and  1   b  applied a stimulus signal to the back to sacral bone  3 . 
         [0054]    In this way, it is possible to determine whether or not a pair of stimulus applying electrodes  1   a  and  1   b  apply an appropriate stimulus on the basis of the potentials (evoked potentials) detected by stimulus-response detecting electrodes  7   a  and  7   b  and stimulus-response detecting electrodes  10   a  and  10   b . In other words, it is possible to determine whether or not a pair of stimulus applying electrodes  1   a  and  1   b  are arranged at appropriate positions on the back of sacral bone  3 . 
         [0055]    If one electrode  1   a  of a pair of stimulus applying electrodes is not arranged at an appropriate position on the back of sacral bone  3 , even when a pair of stimulus applying electrodes  1   a  and  1   b  apply a stimulus signal, the stimulus is not appropriately transmitted to biceps femoris muscle  6  of left leg  5  via sciatic nerve  23 . Therefore, the biological signal is not detected by stimulus-response detecting electrodes  7   a  and  7   b , or only a small biological signal is detected by stimulus-response detecting electrodes  7   a  and  7   b.    
         [0056]    Similarly, if the other electrode  1   b  of the pair of stimulus applying electrodes is not arranged at an appropriate position on the back of sacral bone  3 , even when a pair of stimulus applying electrodes  1   a  and  1   b  apply an electrical stimulus, the stimulus is not appropriately transmitted to biceps femoris muscle  9  of right leg  8  via sciatic nerve  23 . Therefore, the biological signal is not detected by stimulus-response detecting electrodes  10   a  and  10   b , or only a small biological signal is detected by stimulus-response detecting electrodes  10   a  and  10   b.    
         [0057]    The biological signal measured by measuring section  15  is transmitted to control section  16 . Control section  16  displays a measurement result measured by measuring section  15  on display means  17 . The measurement result displayed on display means  17  may be a measurement value itself of the biological signal measured by measuring section  15 , a determination whether or not an appropriate stimulus is transmitted to a nerve passing through the sacral bone or passing near the sacral bone based on the measurement value, or a determination whether or not a pair of stimulus applying electrodes  1   a  and  1   b  are arranged at appropriate positions on the back of sacral bone  3 . 
         [0058]    The determination whether or not an appropriate stimulus is transmitted, or the determination whether or not the stimulus applying electrodes are appropriately arranged is performed by the methods described below. 
         [0059]    (1) A lower limit value of the magnitude (potential difference) of the biological signal to be measured is set in advance, and control section  16  performs the determination on the basis of whether or not the magnitude (potential difference) of the actually measured biological signal exceeds the lower limit value. 
         [0060]    (2) A time period (latent time) until the biological signal is measured is set in advance, and control section  16  performs the determination on the basis of whether or not the actually measured biological signal is measured in the set time period (latent time). The time period until the biological signal is measured is desired to be set to a time period from a time (0 ms) when a stimulus is applied to the back of sacral bone  3  by the stimulus applying electrodes to a time when about 10 to 30 ms will have elapsed. 
         [0061]    For example, if a biological signal detected by stimulus-response detecting electrodes  7   a  and  7   b  arranged on left leg  5  is measured extremely earlier than or later than the set time period (latent time), control section  16  displays that the stimulus transmission from stimulus applying electrode  1   a  is inappropriate on display means  17  or displays that the arrangement of stimulus applying electrode  1   a  is inappropriate on display means  17 . 
         [0062]    On the other hand, if the biological signal detected by stimulus-response detecting electrodes  7   a  and  7   b  is measured around the set time period (latent time), the magnitude (potential difference) of the measured biological signal is compared with the set lower limit value of the magnitude (potential difference) of the biological signal. 
         [0063]    When the magnitude of the measured biological signal is smaller than or equal to the set lower limit value, control section  16  displays that the stimulus transmission from stimulus applying electrode  1   a  is inappropriate on display means  17  or displays that the arrangement of stimulus applying electrode  1   a  is inappropriate on display means  17 . On the other hand, when the magnitude of the measured biological signal is greater than the lower limit value set in control section  16 , control section  16  displays that the stimulus transmission from stimulus applying electrode  1   a  is appropriate on display means  17  or displays that the arrangement of stimulus applying electrode  1   a  is appropriate on display means  17 . 
         [0064]    Similarly, if a biological signal detected by stimulus-response detecting electrodes  10   a  and  10   b  arranged on right leg  8  is measured extremely earlier than or later than the set time period (latent time), control section  16  displays that the stimulus transmission from stimulus applying electrode  1   b  is inappropriate on display means  17  or displays that the arrangement of stimulus applying electrode  1   b  is inappropriate on display means  17 . 
         [0065]    If the biological signal detected by stimulus-response detecting electrodes  10   a  and  10   b  is measured around the set time period (latent time), the magnitude (potential difference) of the measured biological signal is compared with the set lower limit value of the magnitude (potential difference) of the biological signal. 
         [0066]    When the magnitude of the measured biological signal is smaller than or equal to the set lower limit value, control section  16  displays that the stimulus transmission from stimulus applying electrode  1   b  is inappropriate on display means  17  or displays that the arrangement of stimulus applying electrode  1   b  is inappropriate on display means  17 . On the other hand, when the magnitude of the measured biological signal is greater than the lower limit value set in control section  16 , control section  16  displays that the stimulus transmission from stimulus applying electrode  1   b  is appropriate on display means  17  or displays that the arrangement of stimulus applying electrode  1   b  is appropriate on display means  17 . 
         [0067]    It may be difficult to determine whether the signal detected by measuring section  15  is a biological signal generated in response to the stimulus signal or noise. Therefore, measuring section  15  may measure the signal a plurality of times. Specifically, there may be a process in which the biological signal detected by stimulus-response detecting electrodes  7   a  and  7   b  and stimulus-response detecting electrodes  10   a  and  10   b  is measured a plurality of times and a plurality of measured values are averaged. In this case, whether or not an appropriate stimulus is applied or whether or not the stimulus applying electrode is appropriately arranged is determined on the basis of whether or not the averaged biological signal is measured in the set time period (latent time) and whether or not the magnitude of the averaged biological signal is greater than the set lower limit value of the magnitude (potential difference) of the biological signal. 
         [0068]    Further, in a treatment by the urination disorder treatment apparatus of Embodiment 1, a biological signal X detected by stimulus-response detecting electrodes  7   a  and  7   b  arranged on left leg  5  may be compared with a biological signal Y detected by stimulus-response detecting electrodes  10   a  and  10   b  arranged on right leg  8 . Specifically, a time period (latent time) until when the biological signal X is detected may be compared with a time period (latent time) until when the biological signal Y is detected, or the magnitude (potential difference) of the biological signal X may be compared with the magnitude (potential difference) of the biological signal Y. If there is a large difference between the compared latent times or between the compared potential differences, the arrangement state of a pair of stimulus applying electrodes  1   a  and  1   b  is adjusted. Thereby, a pair of stimulus applying electrodes  1   a  and  1   b  are arranged more appropriately, so that it is possible to improve treatment effect. 
         [0069]    As described above, control section  16  can adjust the magnitude of the stimulus signal applied by a pair of stimulus applying electrodes  1   a  and  1   b  according to an operation on operation section  29 . The magnitude of the biological signal detected by stimulus-response detecting electrodes  7   a  and  7   b  and the magnitude of the biological signal detected by stimulus-response detecting electrodes  10   a  and  10   b  can be greater than the set lower limit value by adjusting the magnitude of the stimulus signal. 
         [0070]    The magnitude of the stimulus signal is adjusted according to an individual patient. Because an appropriate magnitude of the stimulus signal to obtain treatment effect on alleviating urination disorder is different for each patient. Therefore, it is preferred to adjust the magnitude of the bipolar square wave pulse signal applied by a pair of stimulus applying electrodes  1   a  and  1   b  by checking treatment effect of each patient. 
         [0071]    A user can check whether or not an appropriate stimulus is transmitted on the basis of information displayed on display means  17 . In other words, the user can perform treatment while the user realizes the treatment effect by the stimulus applied through a pair of stimulus applying electrodes  1   a  and  1   b.    
         [0072]    Hereinafter, embodiments in which the stimulus-response detecting electrodes are arranged differently from those in Embodiment 1 will be described in Embodiments 2 to 4. On the other hand, components other than the stimulus-response detecting electrodes of the urination disorder treatment apparatus of Embodiments 2 to 4 are the same as those in the urination disorder treatment apparatus in Embodiment 1, so that the description thereof will be omitted. 
       Embodiment 2  
       [0073]      FIG. 4  shows an urination disorder treatment apparatus in accordance with Embodiment 2 of the present invention. The stimulus-response detecting electrodes of the urination disorder treatment apparatus of Embodiments 2 are arranged on the backs of semitendinosus muscles  30  and  31  located inside of biceps femoris muscles  6  and  9  (see  FIG. 3 ). Specifically, stimulus-response detecting electrodes  7   a  and  7   b  are arranged on the back of semitendinosus muscle  30  of left leg  5 , and stimulus-response detecting electrodes  10   a  and  10   b  are arranged on the back of semitendinosus muscle  31  of right leg  8 . 
         [0074]    As shown in  FIG. 1  and  FIG. 2 , sciatic nerves  23  pass through sacral foramens  18 . As shown in  FIG. 4 , muscle branches originating from sciatic nerves  23  connect to semitendinosus muscle  30  of left leg  5  and semitendinosus muscle  31  of right leg  8 . 
         [0075]    Therefore, it is possible to determine whether the arrangement state of a pair of stimulus applying electrodes  1   a  and  1   b  is appropriate or not by measuring biological signals detected by stimulus-response detecting electrodes  7   a  and  7   b  arranged on the back of semitendinosus muscle  30  of left leg  5  and stimulus-response detecting electrodes  10   a  and  10   b  arranged on the back of semitendinosus muscle  31  of right leg  8 . As described above, measuring the biological signal includes measuring the latent time and the magnitude (potential difference) of the biological signal. 
       Embodiment 3  
       [0076]      FIG. 5  shows an urination disorder treatment apparatus in accordance with Embodiment 3 of the present invention. The stimulus-response detecting electrodes of the urination disorder treatment apparatus of Embodiments 3 are arranged on the backs of gastrocnemius muscles  24  and  25  located in more distal portions of the legs than biceps femoris muscles  6  and  9  (see  FIG. 3 ) and semitendinosus muscles  30  and  31  (see  FIG. 4 ). Specifically, stimulus-response detecting electrodes  7   a  and  7   b  are arranged on the back of gastrocnemius muscle  24  of left leg  5 , and stimulus-response detecting electrodes  10   a  and  10   b  are arranged on the back of gastrocnemius muscle  25  of right leg  8 . 
         [0077]    As shown in  FIG. 1  and  FIG. 2 , sciatic nerves  23  pass through sacral foramens  18 . As shown in  FIG. 5 , sciatic nerve  23  divides into common peroneal nerve  26  and tibial nerve  27  in a lower portion. The muscle branches of tibial nerves  27  arc connected to gastrocnemius muscles  24  and  25  respectively. 
         [0078]    Therefore, it is possible to determine whether the arrangement state of a pair of stimulus applying electrodes  1   a  and  1   b  is appropriate or not by measuring biological signals detected by stimulus-response detecting electrodes  7   a  and  7   b  arranged on the back of gastrocnemius muscle  24  of left leg  5  and stimulus-response detecting electrodes  10   a  and  10   b  arranged on the back of gastrocnemius muscle  25  of right leg  8 . As described above, measuring the biological signal includes measuring the latent time and the magnitude (potential difference) of the biological signal. 
       Embodiment 4   
       [0079]      FIG. 6  shows an urination disorder treatment apparatus in accordance with Embodiment 4 of the present invention. The stimulus-response detecting electrodes of the urination disorder treatment apparatus of Embodiments 4 are arranged on the backs of posterolateral soleus muscles  33  and  34  located in more distal portions than gastrocnemius muscles  24  and  25  (see  FIG. 5 ). Specifically, stimulus-response detecting electrodes  7   a  and  7   b  are arranged on the back of soleus muscle  33  of left leg  5 , and stimulus-response detecting electrodes  10   a  and  10   b  are arranged on the back of soleus muscle  34  of right leg  8 . 
         [0080]    As shown in  FIG. 1  and  FIG. 2 , sciatic nerves  23  pass through sacral foramens  18 . As shown in  FIG. 6 , sciatic nerve  23  divides into common peroneal nerve  26  and tibial nerve  27  in a lower portion. The muscle branches of tibial nerves  27  are connected to soleus muscles  33  and  34  respectively. 
         [0081]    Therefore, it is possible to determine whether the arrangement state of a pair of stimulus applying electrodes  1   a  and  1   b  is appropriate or not by measuring biological signals detected by stimulus-response detecting electrodes  7   a  and  7   b  arranged on the back of soleus muscle  33  of left leg  5  and stimulus-response detecting electrodes  10   a  and  10   b  arranged on the back of soleus muscle  34  of right leg  8 . As described above, measuring the biological signal includes measuring the latent time and the magnitude (potential difference) of the biological signal. 
       INDUSTRIAL APPLICABILITY 
       [0082]    As described above, the urination disorder treatment apparatus of the present invention treats a urination disorder by transmitting a stimulus signal to a nerve which passes through the sacral micturition reflex center and controls collection and discharge of urine through at least a pair of stimulus applying electrodes arranged on the back of the sacral bone with a predetermined distance between them. The urination disorder treatment apparatus of the present invention includes the stimulus-response detecting electrodes and can detect a biological signal generated in response to the stimulus signal. It is possible to display whether or not an appropriate biological signal is given on the display means by measuring the biological signal. The therapist can appropriately adjust the arrangement position of a pair of stimulus applying electrodes so that an appropriate stimulus signal is applied while checking the display. Thereby, an appropriate treatment is realized. 
         [0083]    When the urination disorder treatment apparatus of the present invention includes an operation section for adjusting the strength of the stimulus signal, the therapist can adjust the strength of the stimulus signal by operating the operation section to apply an appropriate stimulus signal while checking the display, so that the therapist can apply a stimulus appropriate for the patient. 
         [0084]    As described above, the urination disorder treatment apparatus of the present invention can realize a more effective treatment of urination disorder. 
         [0085]    This application claims the priority of Japanese Patent Application No. 2009-215361 filed Sep. 17, 2009, which is hereby incorporated by reference herein in its entirety, including the specification, claims, and drawings. 
       Reference Signs List 
       [0000]    
       
           1   a ,  1   b  A pair of stimulus applying electrodes 
           2  Human body 
           3  Sacral bone 
           4  Stimulus signal supply source 
           5  Left leg 
           6 ,  9  Biceps femoris muscle 
           7   a ,  7   b  stimulus-response detecting electrode 
           8  Right leg 
           10   a ,  10   b  stimulus-response detecting electrode 
           11 ,  13  Short head of biceps femoris muscle 
           12 ,  14  Long head of biceps femoris muscle 
           15  Measuring section 
           16  Control section 
           17  Display means 
           18  Sacral foramens 
           19  Urine bladder 
           20  Pelvic splanchnic nerve 
           21  Urethral sphincter muscle 
           22  Pudendal nerve 
           23  Sciatic nerve 
           24 ,  25  Gastrocnemius muscle 
           26  Common peroneal nerve 
           27  Tibial nerve 
           28  Hypogastric nerve 
           29  Operation section 
           30 ,  31  Semitendinosus muscle 
           32  Ground electrode 
           33 ,  34  Soleus muscle