Patent Publication Number: US-2010125024-A1

Title: Rocking-type exercise device

Description:
FIELD OF THE INVENTION 
     The present invention relates to a rocking-type exercise device for applying an exercise load to a user sat on a seat by subjecting the seat to rocking movement. 
     BACKGROUND OF THE INVENTION 
     Conventionally, there are proposed a variety of rocking-type exercise devices for applying an exercise load to a user sat on a seat by subjecting the seat to rocking movement. The rocking-type exercise devices are simple and convenient exercise machines that can be used by anybody from children to old persons. The rocking-type exercise devices have been spread to rehabilitation-purpose medical institutions and then to general households. One typical prior art example of the rocking-type exercise devices is disclosed in, e.g., Japanese Patent Laid-open Publication No. 2006-149468. 
     In the rocking-type exercise device disclosed in Japanese Patent Laid-open Publication No. 2006-149468, a pressure sensor or the like is provided in at least one of, e.g., the upper surface of the seat, the side surface of the seat (or the saddle flap) and the inside of the stirrup. The exercise posture of a user is determined from the information provided by the pressure sensor. In this rocking-type exercise device, the seat is configured to make reciprocating movement in response to the notification of an exercise posture based on the detected information or in response to the detected information itself. 
     Although the rocking-type exercise device cited above proposes a configuration in which a notification unit is used to urge a user to correct his or her posture, it fails to suggest a method for accurately leading the user&#39;s posture or motion to a target one. Thus, demand has existed for the development of a rocking-type exercise device capable of bringing the user&#39;s posture into close proximity to a target posture with increased accuracy. 
     SUMMARY OF THE INVENTION 
     In view of the above, the present invention provides a rocking-type exercise device capable of accurately leading the user&#39;s exercise posture to a target exercise posture. 
     In accordance with a first aspect of the invention, there is provided a rocking-type exercise device including: 
     a seat on which a user can sits; a seat rocking unit for reciprocating the seat at least in one direction; a control unit for controlling the seat rocking unit so as to reciprocate the seat; and a detector unit for detecting a user&#39;s exercise posture to obtain detected information, wherein the control unit includes a feedback stimulus output unit for comparing the detected information obtained by the detector unit with a target value and for outputting, if a difference exits between the detected information and the target value, a feedback stimulus by which to make the detected information come close to the target value. 
     With such configuration, by outputting the feedback stimulus by which to make the detected information come close to the target value depending on the difference between the detected information and the target value, it is possible to accurately lead the user&#39;s exercise posture to a target exercise posture corresponding the target value. The term “feedback stimulus” used herein denotes a stimulus for guiding the user&#39;s exercise posture by at least one of a sound, an image, a seat operation amount and a seat operation pattern. Hereinafter, the term “feedback stimulus” will be used in this sense. 
     The feedback stimulus outputted by the feedback stimulus output unit may be kept unchanged in meaning but changed in expression over time. 
     In this regard, description will be made on a sound as the feedback stimulus. In case where the user takes a target exercise posture, it may be conceivable to generate feedback stimuli identical in meaning but differing in expression, e.g., voices saying “good job”, “it&#39;s OK” and “keep it up”. By outputting the feedback stimuli identical in meaning but differing in expression over time, it becomes possible to avoid application of monotonous stimuli and to keep the user from getting weary. This makes it possible to keep the user motivated. Even in an instance where the user has a difficulty in understanding a specific feedback stimulus, it is possible to help the user understand the feedback stimulus by outputting a feedback stimulus of other expression. This assists in coping with the difference among individual users. 
     The feedback stimulus output unit may be configured to redefine the target value or the feedback stimulus based on the detected information, if the detected information fails to come close to the target value for a predetermined time period in spite of the outputting of the feedback stimulus by which to make the detected information come close to the target value. 
     With such configuration, it is possible to set a user-specific target value or to output a user-specific feedback stimulus. In addition, the above configuration makes it possible to reduce the target value or to output a safety-purpose feedback stimulus. As a result, the user can safely use the present device with no overwork even when the user has reduced physical strength or when the target value set at first is too high. 
     In the rocking-type exercise device, if the detected information is kept smaller than the target value for a predetermined time period, the feedback stimulus output unit may reduce the target value or output a safety-purpose feedback stimulus in order for the seat to safely make the reciprocating movement. 
     With such configuration, the user can safely use the present device with no overwork even when the user has reduced physical strength or when the target value set at first is too high. 
     In the rocking-type exercise device, the feedback stimulus output unit may be configured to stop outputting the feedback stimulus, if the detected information fails to come close to the target value for a predetermined time period in spite of the outputting of the feedback stimulus by which to make the detected information come close to the target value. 
     In other words, if the detected information fails to come close to the target value, it is determined that the target value is too high or the user gets tired. Thus, the feedback stimulus output unit ceases to output the feedback stimulus. This makes it possible for the user to safely perform an exercise in a favored posture with no overwork, instead of compelling the user to do an exercise at the target value. 
     In the rocking-type exercise device, the detector unit may include a plurality of posture detector units for detecting postures of different bodily parts of the user to get a plurality of detected posture information, and wherein the feedback stimulus output unit may be configured to output feedback stimuli reflecting the difference between the detected posture information and the target value in the order of greater deviation of the detected posture information from the target value. 
     In other words, depending on the difference between the detected information for the respective bodily parts and the target value, feedback stimuli are outputted one after another in the order of greater deviation of the detected information from the target value. By merely moving the bodily parts in response to the feedback stimuli thus outputted, the user can accurately take a target exercise posture (corresponding to the target value). 
     In the rocking-type exercise device, the detector unit may include a plurality of posture detector units for detecting postures of different bodily parts of the user, the posture detector units being given a priority order, and wherein the feedback stimulus output unit may be configured to output feedback stimuli in the priority order. 
     In other words, the posture detector units are given a priority order in which to output feedback stimuli regardless of the difference between the detected information of the posture detector units and the target value. By outputting feedback stimuli in the priority order, it is possible to urge the user to accurately take the target exercise posture without having to recognize the operation order which is important in leading the user to the target exercise posture. 
     In the rocking-type exercise device, the feedback stimulus output unit may include a notification unit through which to notify the user of the feedback stimulus or the feedback stimuli by at least one of a voice and an image, and wherein the feedback stimulus output unit may be configured to output, when notification is performed by the notification unit, the feedback stimulus or the feedback stimuli together with incidental effects varying with the difference between the detected information and the target value. 
     In other words, at least one of the voice and the image is not merely outputted as the feedback stimulus or the feedback stimuli but outputted together with incidental effects varying with the difference between the detected information and the target value. This helps prevent the feedback stimulus or the feedback stimuli from becoming monotonous, which makes it possible to keep the user highly motivated. 
     In the rocking-type exercise device, the feedback stimulus output unit may be configured to output the feedback stimulus or the feedback stimuli after altering the emotion-appealing information contained in the feedback stimulus or the feedback stimuli depending on the difference between the detected information and the target value. 
     Use of this configuration helps prevent the feedback stimulus or the feedback stimuli from becoming monotonous, which makes it possible to keep the user highly motivated. 
     In the rocking-type exercise device, the feedback stimulus output unit may be configured to output the feedback stimulus or the feedback stimuli in such a way as to remind the user of the moving images of the bodily parts. 
     In this regard, description will be made on a sound as the feedback stimulus. In order to remind the user of the moving images of the bodily parts, the names of the user&#39;s bodily parts may be mentioned by, e.g., saying “bend the knees” or “stretch the legs” or a metaphor may be used by, e.g., saying “make round as if hugging the knees” or “stretch the legs straight”. This makes it possible to accurately lead the user to the target exercise posture (corresponding to the target value). Accordingly, it is possible to draw the user&#39;s attention to the bodily parts at issue, which assists in effectively leading the user to the target exercise posture. 
     With the present invention, it is possible to provide a rocking-type exercise device capable of accurately leading the user&#39;s exercise posture to a target exercise posture. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The objects and features of the present invention will become apparent from the following description of embodiments, given in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a side view showing the overall configuration of a rocking-type exercise device in accordance with the present embodiment; 
         FIG. 2  is a side view of a seat rocking mechanism employed in the rocking-type exercise device; 
         FIG. 3  is a plan view of the seat rocking mechanism; 
         FIG. 4  is a front view of the seat rocking mechanism; 
         FIG. 5  is a view for explaining sensors employed in the rocking-type exercise device; 
         FIG. 6  is a block diagram illustrating a schematic system configuration of the rocking-type exercise device; 
         FIG. 7  is a flowchart for explaining a method of outputting a vocal feedback stimulus; 
         FIG. 8  is a view for explaining a feedback data selection table; 
         FIGS. 9A and 9B  are views for explaining feedback data selection tables in accordance with additional examples; 
         FIG. 10  is a view for explaining a feedback data selection table in accordance with a further additional example; 
         FIG. 11  is a view for explaining a feedback data selection table in accordance with a still further additional example; 
         FIG. 12  is a flowchart for explaining a method of outputting a vocal feedback stimulus in accordance with an additional example; 
         FIG. 13  is a flowchart for explaining a method of outputting a vocal feedback stimulus in accordance with a further additional example; 
         FIG. 14  is a view for explaining a feedback data selection table in accordance with an additional example; 
         FIGS. 15A and 15B  are views for explaining exercise postures in accordance with additional examples, and  FIG. 15C  is a view for explaining a feedback data selection table; 
         FIGS. 16A ,  16 B and  16 C are views for explaining feedback data selection tables in accordance with additional examples; 
         FIGS. 17A ,  17 B and  17 C are views for explaining exercise postures in accordance with additional examples; 
         FIG. 18  is a view for explaining a feedback data selection table in accordance with an additional example; 
         FIG. 19  is a view for explaining a feedback data selection table in accordance with a further additional example; and 
         FIG. 20  is a view for explaining a feedback data selection table in accordance with a still further additional example. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, one embodiment of the present invention will be described with reference to  FIGS. 1 through 9 . 
     As shown in  FIG. 1 , the rocking-type exercise device  10  includes a leg  11  mounted on a floor surface not shown in the drawings, a seat rocking mechanism  12  as a seat rocking unit fixed to the top end of the leg  11 , and a seat  13  fixed to the upper portion of the seat rocking mechanism  12 . The seat  13 , on which a user can sit, has a shape imitating a horseback or a saddle. The seat rocking mechanism  12  is configured to cause back-and-forth and left-and-right rocking motions to the seat  13 . The seat rocking mechanism is covered with a cover  14  extending between the upper end of the leg  11  and the seat  13 . The cover  14  is made of a pliable fabric or the like, thereby allowing the seat  13  to be rocked by the seat rocking mechanism  12 . Alternatively, the cover  14  may be formed of plural kinds of other materials. 
     An operation unit  15  is arranged in the frontal portion (on the left side in  FIG. 1 ) of the top surface of the seat  13 . The startup, stoppage and operation state change of the seat rocking mechanism  12  are performed by operating switches (not shown) provided in the operation unit  15 . 
     In the so-called saddle flap lying on the frontal side surface of the seat  13  and making contact with the inner part of a thigh, a pressure sensor α as a detector unit is arranged as shown in  FIG. 5  to measure the pressure applied to the saddle flap. A so-called stirrup  16 , on which the user&#39;s foot sole can be placed, is arranged in a rockable manner. An angle sensor β is arranged in the stirrup  16  to measure the angle of the stirrup  16  so that the angle of the knee can be estimated by a microcomputer  17  (see  FIG. 6 ) set forth below. 
     Next, the seat rocking mechanism  12  will be schematically described with reference to  FIGS. 1 through 4 . 
     As can be seen in  FIG. 3 , a base  21  of rectangular plate shape is fixed to the upper surface of the leg  11  shown in  FIG. 1 . Referring to  FIG. 2 , a pair of front and rear shaft-supporting plates  22  is installed upright in the base  21 . A pair of connecting plates  24  depending from the front and rear end portions of a movable trestle  23  is arranged in an opposing relationship with the shaft-supporting plates  22 . The shaft-supporting plates  22  and the connecting plates  24  are rotatably interconnected by pivot shafts  25  extending in the back-and-forth direction. The pivot shafts  25  are arranged at the transverse center of the base  21  and at two points spaced apart in the back-and-forth direction, thereby supporting the movable trestle  23  so that it can rotate in the transverse direction. 
     As shown in  FIG. 2 , a platform  27  for holding the seat  13  is arranged above the movable trestle  23  and is connected to the movable trestle  23  through connecting links  26  so that it can rock in the back-and-forth direction. More specifically, as shown in  FIG. 4 , a pair of side plates  30  extending in the back-and-forth direction is installed in the left and right portions of the movable trestle  23 . As can be seen in  FIG. 3 , the connecting links  26  include a front link  26   a  arranged at the front side and a rear link  26   b  arranged at the rear side. Referring again to  FIG. 2 , the lower end portion of the front link  26   a  is pivotally attached to a lower pivot pin  31   a  provided in the front end portions of the side plates  30 . The upper end portion of the front link  26   a  is pivotally attached to an upper pivot pin  32   a  provided in the front end portion of the platform  27 . In addition, the lower end portion of the rear link  26   b  is pivotally attached to a lower pivot pin  31   b  provided in the rear end portions of the side plates  30 . The upper end portion of the rear link  26   b  is pivotally attached to an upper pivot pin  32   b  provided in the rear end portion of the platform  27 . The front and rear lower pivot pins  31   a  and  31   b  constitute transverse shafts for supporting the connecting links  26  so that they can rotate about transverse axes. This enables the platform  27  to reciprocatingly rotate about the transverse shafts in the back-and-forth direction as indicated by an arrow M in  FIG. 2 . As shown in  FIG. 4 , the platform  27  is connected to the movable trestle  23  by the connecting links  26  and is swung in the transverse direction together with the movable trestle  23 . Therefore, the platform  27  can be reciprocatingly rotated about the pivot shafts  25  in the transverse direction as indicated by an arrow N in  FIG. 4 . 
     The distance between the front and rear lower pivot pins  31   a  and  31   b  is set shorter than the distance between the front and rear upper pivot pins  32   a  and  32   b . Therefore, the rear link  26   b  makes a specified angle with respect to the base  21  when the front link  26   a  makes a generally right angle relative to the base  21  as indicated by solid lines in  FIG. 2 . As a result, the rear end of the platform  27  becomes lower than the front end thereof, meaning that the platform  27  is tilted backwards. In contrast, the front link  26   a  makes a specified angle with respect to the base  21  when the rear link  26   b  makes a generally right angle relative to the base  21  as indicated by phantom lines in  FIG. 2 . As a consequence, the front end of the platform  27  becomes lower than the rear end thereof, meaning that the platform  27  is tilted forwards. Consequently, the seat  13  fixed to the platform  27  is caused to make tilting movement forwards and backwards. 
     A drive unit  35  is accommodated between the base  21  and platform  27 . The drive unit  35  includes a motor  36  fixed to the base  21  so that the output shaft  37  thereof can protrude upwards. A motor gear  38  is fixed to the output shaft  37 . A first gear  40  engages with the motor gear  38 . The first gear  40  is coaxially fixed to a first shaft  39  whose transverse ends are pivotally supported on the platform  27 . An eccentric crank  41  is connected to one end portion of the first shaft  39 . The first end portion of an arm link  43  is pivotally attached to the eccentric crank  41  by a pivot pin  42 , while the second end portion of the arm link  43  is pivotally attached to the front link  26   a  by a pivot pin  44 . As the eccentric crank  41  makes eccentric circular movement with respect to the first shaft  39  upon rotation of the motor  36 , the front link  26   a  reciprocates in the back-and-forth direction X and the seat  13  makes rocking movement in the direction indicated by the arrow M in  FIG. 2 . As can be seen in  FIGS. 2 and 3 , the motor  36  (the output shaft  37 ), the motor gear  38 , the first shaft  39 , the first gear  40 , the eccentric crank  41  and the arm link  43  constitute a first drive unit. 
     As shown in  FIG. 3 , an interlocking gear  45  is fixed to the first shaft  39  engages with a second gear  47  which is fixed to a second shaft  46  pivotally supported on the movable trestle  23 . The upper end of an eccentric rod  48  is connected to one end (the right end in  FIG. 4 ) of the second shaft  46  by a pivot pin  49  in an eccentric relationship with the rotational axis of the second shaft  46 . The lower end of the eccentric rod  48  is rotatably connected to a connecting bracket  50  by a pivot pin  51 . The connecting bracket  50  is fixed to the base  21 . As the upper end of the eccentric rod  48  makes eccentric circular movement by the rotation of the second shaft  46 , the movable trestle  23 , namely the platform  27  and the seat  13 , makes rocking movement in the direction indicated by the arrow N in  FIG. 4 . As can be seen in  FIGS. 2 through 4 , the motor  36  (the output shaft  37 ), the motor gear  38 , the first gear  40 , the first shaft  39 , the second shaft  46 , the second gear  47  and the eccentric rod  48  constitute a second drive unit. 
     The gear ratios of the respective gears in the first drive unit and the second drive unit are set to ensure that the seat  13  reciprocates twice in the back-and-forth direction while reciprocating once in the transverse direction. Therefore, the seat  13  is rocked in such a way as to describe the numeral “8” when the rocking-type exercise device  10  is seen from above, consequently reproducing an operation just like horse riding. 
     By the first and second drive units configured as above, the seat  13  is rocked in the direction indicated by the arrow M in  FIG. 2  and in the direction indicated by the arrow N in  FIG. 4 . As a result of this combined rocking movement, the seat  13  is rocked in the θX direction around an X-axis, the θY direction around a Y-axis and the θZ direction around a vertical axis (or a Z-axis). This enables a user to train a body balance function and an exercise function. Furthermore, three motions can be performed by a single motor  36 , which assists in reducing the number of motor. This leads to ease of control and reduction in cost and size. In addition, the output shaft  37  of the motor  36  protrudes in one direction and the motor is installed in vertical orientation. This makes it possible to achieve size reduction by narrowing the installation space of the seat rocking mechanism  12  including the motor  36 . The seat rocking mechanism  12  is stored between the base  21  and the platform  27 , which makes it possible to faithfully reproduce the desired horse riding operation. 
       FIG. 6  is a block diagram illustrating a system configuration of the rocking-type exercise device  10 . A power supply unit  61  carried by a circuit board  60  is designed to convert a commercial alternating current inputted through a power supply plug (not shown) to a direct current of 140V or 15V and then to supply the direct current to individual circuits provided in the circuit board  60 . A control circuit  62  as a control unit is mounted to the circuit board  60 . The control circuit  62  includes a microcomputer  17  as a feedback stimulus output unit and a memory  63  which stores drive operation patterns and the like. The control circuit  62  is connected to a sensor unit  64 , which includes the angle sensor β and the pressure sensor α, a voice signal processing IC  65  and a database  66 . 
     As mentioned above, the angle sensor β detects the angle of the stirrup  16 . Based on the result of detection of the angle sensor β, the microcomputer  17  estimates the knee angle of a user. The pressure sensor α detects the pinching force of the user&#39;s thigh and outputs the result of detection to the microcomputer  17 . 
     A voice data storage unit  67  and a speaker  68 , which constitutes the feedback stimulus output unit and the notification unit, are connected to the voice signal processing IC  65 . Thus, the voice signal processing IC  65  can notify the speaker  68  of, e.g., music data pre-stored in the voice data storage unit  67 . 
     Tables corresponding to various kinds of operation patterns, such as a feedback data selection table group  69  and the like, are stored in the database  66 . 
     Next, one example of the output of a vocal feedback stimulus in the rocking-type exercise device  10  of the present embodiment will be described with reference to  FIGS. 6 and 7 . 
     The pinching force (pressure) of the user&#39;s thigh is detected by the pressure sensor α and the result of detection is outputted from the pressure sensor α to the microcomputer  17  of the control circuit  62  (step S 100 ). The microcomputer  17  acquires the result of detection (step S 200 ). After sampling the detection results for a specified time, the microcomputer  17  calculates a representative value S n , i.e., an average value of the detection results outputted from the pressure sensor α (step S 300 ). 
     Then, the microcomputer  17  compares the representative value S n  with threshold values pre-divided into a plurality of steps (five steps in the present embodiment) as illustrated in  FIG. 8  (step S 400 ). Based on a specified data selection table (see  FIG. 8 ) within the feedback data selection table group  69  of the database  66  shown in  FIG. 6 , the microcomputer  17  selects the feedback voice data stored in the voice data storage unit  67  through the voice signal processing IC  65  (step S 500 ). In the present embodiment, the threshold values are set in the order of 1V, 2V, 3V, 4V and 5V from the lower side, and the target value indicative of a target exercise posture is set equal to 3V. The feedback voice data outputted depending on the representative value S n  are also shown in  FIG. 8 . If the representative value S n  is equal to the threshold value 1V, the microcomputer  17  selects the data of “with far greater force.wav” which is a voice record saying “with far greater force”. If the representative value S n  is equal to the threshold value 2V, the microcomputer  17  selects the data of “with a little greater force.wav” which is a voice record saying “with a little greater force”. If the representative value S n  is equal to the threshold value 3V (or the target value), the microcomputer  17  selects the data of “it&#39;s OK.wav” which is a voice record saying “it&#39;s OK”. If the representative value S n  is equal to the threshold value 4V, the microcomputer  17  selects the data of “relax a little bit.wav” which is a voice record saying “relax a little bit”. If the representative value S n  is equal to the threshold value 5V, the microcomputer  17  selects the data of “relax.wav” which is a voice record saying “relax”. 
     Then, the microcomputer  17  allows the speaker  68  to output the feedback voice data selected in step  5500  (step S 600 ). Thereafter, the microcomputer  17  is operated to repeat step S 100  through step S 600 . 
     By employing the afore-mentioned configuration in which a voice as a feedback stimulus is outputted from the speaker  68  depending on the difference between the target value 3V and the representative value Sn, i.e., the average value of the detection results outputted from the pressure sensor α, the user can recognize the difference between the target posture and the current posture. This makes it possible to lead the user&#39;s posture so that the representative value S n  can become equal to the target value 3V. Thus, it becomes possible to rapidly and accurately lead the user&#39;s exercise posture to the target posture. 
     Next, description will be made on the advantageous effects specific to the present embodiment. 
     The control circuit  62  as a control unit includes the pressure sensor α as a detector unit for detecting the exercise posture of the user who sits on the seat  13 , and the microcomputer  17  as a feedback stimulus output unit that makes comparison between the detected information (representative value S n ) obtained in the pressure sensor α and the target value (or the threshold values 3V). Depending on the difference between the detected information and the target value, the microcomputer  17  outputs through the speaker  68  a voice for making the representative value S n  come close to the target value. By outputting the voice for making the representative value S n  come close to the target value depending on the difference between the detected information and the target value, it is possible to rapidly and accurately lead the user&#39;s exercise posture to the target exercise posture corresponding the target value. 
     The embodiment of the present invention may be modified as follows. 
     Although only one feedback data selection table is used to apply a vocal feedback stimulus to the user in the foregoing embodiment, the present invention is not limited thereto. As an alternative example, a plurality of feedback data selection tables may be used as shown in  FIGS. 9A and 9B . 
     At this time, a posture/operation determination algorithm  70  stored in the database  66  may be called out by the microcomputer  17  so that the algorithm  70  can change the feedback data selection tables of the feedback data selection table group  69  over time. In this case, it may be possible to employ a configuration in which only the wording of the voice data applied to the user is changed over time without changing the meaning thereof. More specifically, it may be conceivable to employ a configuration in which the data of “it&#39;s OK.wav” selected in case of the threshold value 3V in the foregoing embodiment is changed to the data of “keep it up.wav” which is a voice record saying “keep it up” as illustrated in  FIG. 9A  and then the changed data is outputted from the speaker  68 . Thereafter, the data of “keep it up.wav” is changed to the data of “good.wav” which is a voice record saying “good” as illustrated in  FIG. 9B  and then the changed data is outputted from the speaker  68 . By outputting the vocal feedback stimuli identical in meaning but differing in expression over time, it becomes possible to avoid application of monotonous stimuli and to keep the user from getting weary. This makes it possible to keep the user motivated. Even in an instance where the user has a difficulty in understanding a specific feedback stimulus (e.g., the data of “it&#39;s OK.wav”), it is possible to help the user understand the feedback stimulus by outputting a feedback stimulus of other expression (e.g., the data of “keep it up.wav”). This assists in coping with the difference among individual users. 
     Although the target value is set equal to the threshold value 3V in the foregoing embodiment, the present invention is not limited thereto. As shown in  FIG. 10 , the threshold values 2V and 3V may be used as target values without having to limit the target value to a single one. 
     The configuration noted above is effective in broadening the width of target value by setting the threshold values 2V and 3V as target values, in such an instance where the representative value S n  fails to reach the target value even when a voice as a feedback stimulus has been outputted from the speaker  68  as a feedback stimulus output unit while the user using the rocking-type exercise device  10  for a predetermined time period. The broadened target value allows a user with a weak muscular force to safely use the rocking-type exercise device  10  with no overwork. By changing the target value depending on the detected information (or the representative value S n ) in this manner, it becomes possible to set a user-specific target value. 
     Although the voltages of 1V through 5V are used as the threshold values in the foregoing embodiment, the present invention is not limited thereto. In the feedback data selection table illustrated in  FIG. 8 , the threshold values are set into five steps of 1V, 2V, 3V (target value), 4V and 5V. During the course of using the rocking-type exercise device  10 , the threshold values may be changed to five steps of, e.g., 0.5V, 1V, 1.8V (target value), 2.5V and 3.5V, as illustrated in  FIG. 11 . 
     The configuration by which to reduce the threshold values in the course of using the rocking-type exercise device  10  can be effectively used in such an instance where the detected information from the sensors (e.g., the pressure sensor α) fails to reach the target value (namely, in case where the detected information is smaller than the target value) even when a voice as a feedback stimulus has been outputted from the speaker  68  as a feedback stimulus output unit while the user using the rocking-type exercise device  10  for a predetermined time period. The reduction in the target value results in a reduction in exercise amount and sets a user free from excessive burdens. Even if the target value set at first is too high, the user can safely use the rocking-type exercise device  10  with no overwork. By changing the target value depending on the detected information (or the representative value S n ) in this manner, it becomes possible to set a user-specific target value. 
     Alternatively, a configuration in which only the target value is changed may be employed as illustrated in  FIG. 12 . In the configuration shown in  FIG. 12 , steps for lowering the target value are added between step S 300  and step S 400  of the flowchart illustrated in  FIG. 7 . More specifically, the microcomputer  17  temporarily stores in the memory  63  the representative values, i.e., the average values of the detected information successively supplied from the pressure sensor α, as S n , S n−1  and S n−2  in the order of latest occurrence. The microcomputer  17  compares the representative values S n , S n−1  and S n−2  with the target value (step S 301 ). If the representative values S n , S n−1  and S n−2  are smaller than the target value (or if YES in step S 301 ), the target value is multiplied by a predetermined numerical value (of smaller than 1), thereby reducing the target value into a new target value (step S 302 ). Then, the flow proceeds to step S 400  already described in respect of the foregoing embodiment. If the representative values S n , S n−1  and S n−2  are equal to or greater than the target value (or if NO in step S 301 ), the microcomputer  17  does not change the target value and the flow proceeds to step S 400  already described in respect of the foregoing embodiment. By changing the target value depending on the detected information (or the representative value S n ) in this manner, it becomes possible to set a user-specific target value. In addition, if the detected information supplied from the detector unit (or the representative value S n ) is kept smaller than the target value for a predetermined time period, the target value is set smaller so that the rocking operation can be performed in a safe way. As a result, the user can safely use the present device  10  with no overwork even when the user has reduced physical strength or when the target value set at first is too high. 
     Although not specifically mentioned in the foregoing embodiment, the target value may be kept unchanged in order to safely perform the reciprocating movement, if the detected information supplied from the pressure sensor α as a detector unit remains smaller than the target value (or the threshold value 3V) for a predetermined time period. For example, it may be conceivable to employ a configuration by which to output a voice data of “it&#39;s OK.wav” or other voice data as a safety-purpose feedback stimulus through the speaker  68 . Employment of this configuration helps prevent a user from taking an overload posture, thereby enabling the user to safely use the present device  10 . 
     Although not specifically mentioned in the foregoing embodiment, it may be conceivable to employ a configuration in which, if the representative value S n  as the detected information supplied from the pressure sensor α does not come close to or gets away from the target value (or the threshold value 3V), the feedback control is stopped by not outputting the voice as a feedback stimulus through the speaker  68 , namely by ceasing to output the feedback stimulus. 
     More specifically, as illustrated in  FIG. 13 , the microcomputer  17  temporarily stores in the memory  63  the representative values, i.e., the average values of the detected information successively supplied from the pressure sensor α, as S n , and S n−1  and S n−2  in the order of latest occurrence. The microcomputer  17  calculates the difference U n  between S n  and S n−1  which precedes S n , and the difference U n−1  between S n−1  and S n−2  which precedes S n−1  (step S 310 ). Then, the microcomputer  17  determines whether the differences U n  and U n−1  are all smaller than zero (step S 320 ). If the differences U n  and U n−1  are all determined to be smaller than zero (or if YES in step S 320 ), a voice saying “don&#39;t overstrain if tired” is outputted through the speaker (step S 330 ). If the differences U n  and U n−1  are all determined to be equal to or greater than zero (or if NO in step S 320 ), the microcomputer  17  proceeds to step S 400  already described in respect of the foregoing embodiment. At the end of step S 330 , the microcomputer  17  asks the user, e.g., through the speaker  68 , whether to terminate the feedback control for guiding the exercise posture by a voice (step S 340 ). If the user selects the termination of feedback control using a switch not shown (or if YES in step S 340 ), the microcomputer  17  ceases to output the voice as a feedback stimulus and stops the feedback control for guiding the exercise posture by a voice (step S 350 ). In contrast, if the user does not select the termination of feedback control (or if NO in step S 340 ), the flow proceeds to step S 400  already described in respect of the foregoing embodiment. 
     As set forth above, if the detected information fails to come close to the target value, it is determined that the target value is too high or the user got tired. Thus, the microcomputer  17  ceases to output the feedback stimulus (or the voice). This makes it possible for the user to safely perform an exercise in a favored posture with no overwork, instead of compelling the user to do an exercise at the target value. 
     In the foregoing embodiment, only one sensor (i.e., the pressure sensor α) is used when the voice as a feedback stimulus is outputted through the speaker  68  depending on the difference between the detected information and the target value. Alternatively, a plurality of sensors (e.g., the pressure sensor α and the angle sensor β) may be used in outputting the voice as a feedback stimulus through the speaker  68 . 
     In addition to the above, it may be conceivable to employ a configuration in which voices as feedback stimuli are outputted one after another through the speaker  68  in the order of greater deviation or badness of the detected information (or the representative value S n ) from the target value. More specifically, if the target values of the pressure sensor α and the angle sensor β are all 3V as illustrated in  FIG. 14  and if the detected information (or the representative value S n ) of the pressure sensor α is 1V with the detected information (or the representative value S n ) of the angle sensor β being 2V or 3V, the microcomputer  17  may output feedback stimuli (e.g., voices) for improving the detected information of the pressure sensor α as illustrated in  FIG. 14 . In other words, depending on the difference between the detected information (or the representative value S n ) for the respective bodily parts and the target value, feedback stimuli (e.g., voices) are outputted one after another in the order of greater deviation of the detected information for the respective bodily parts from the target value. By merely moving the bodily parts in response to the feedback stimuli thus outputted, the user can accurately take a target exercise posture (corresponding to the target value). 
     It may also be conceivable to employ a configuration in which a priority order is applied to the respective sensors α and β and voices as feedback stimuli are outputted through the speaker  68  in the priority order. For example, the user may be urged to change his or her posture from the state illustrated in  FIG. 15A  in which the lower half of the user&#39;s body (or the legs) is stretched and propped to the state illustrated in  FIG. 15B  in which the lower half of the user&#39;s body (or the legs) is bent. In this case, it is necessary to urge the user to reduce the angle of the knees prior to reducing the pinching force of the thighs. If the knee angle is not equal to the target value “small” as shown in  FIG. 15C , a voice as a feedback stimulus for improving the detected information (or the representative value S n ) of the angle sensor β is outputted through the speaker  68 , thereby urging the user to pay attention to the knee angle. Once the knee angle becomes equal to the target value “small”, a voice as a feedback stimulus for improving the detected information (or the representative value S n ) of the pressure sensor α is outputted through the speaker  68 . In other words, the pressure sensor α and the angle sensor β are given a priority order in which to output feedback stimuli (e.g., voices) regardless of the difference between the detected information of the respective sensors and the target value. By outputting feedback stimuli (e.g., voices) in the priority order, it is possible to urge the user to accurately take the target exercise posture without having to recognize the operation order which is important in leading the user to the target exercise posture. 
     Although not specifically mentioned in the foregoing embodiment, it may be conceivable to employ a configuration in which the emotion-appealing information of a voice is altered by changing the voice data to the ones showing encouragement or appreciation for the user&#39;s efforts. More specifically, the feedback data selection table shown in  FIG. 16A  may be changed to a feedback data selection table illustrated in  FIG. 16B , which indicates the voice data containing the emotion-appealing information for encouragement, or a feedback data selection table depicted in  FIG. 16C , which indicates the voice data containing the emotion-appealing information for appreciation. In this case, it is preferred that the content of the emotion-appealing information is changed depending on the difference between the target value and the detected information (or the representative value S n ). Use of this configuration helps prevent the feedback stimulus from becoming monotonous, which makes it possible to keep the user motivated. 
     Although not specifically mentioned in the foregoing embodiment, it may be conceivable to employ a configuration by which to output a feedback stimulus specifying the names of components making contact with the user&#39;s bodily parts. For example, it may be possible to employ a configuration in which the voice data of “let&#39;s lower the stirrup.wav”, i.e., a voce record saying “let&#39;s lower the stirrup”, is selected when the user&#39;s posture is to be changed from the state illustrated in  FIG. 17A , in which the legs are stretched, to the state shown in  FIG. 17B , in which the shins are oriented vertically downwards. 
     Although not specifically mentioned in the foregoing embodiment, it may be conceivable to employ a configuration by which to output a feedback stimulus mentioning the user&#39;s bodily parts. For example, it may be possible to employ a configuration in which the voice data of “further stretch the knees.wav” illustrated in  FIG. 19 , i.e., a voice record saying “further stretch the knees”, is selected when the user&#39;s posture is to be changed from the state illustrated in  FIG. 17C , in which the shins are bent, to the state shown in  FIG. 17B , in which the knees are stretched to some extent. Alternatively, it may be possible to employ a configuration by which to select the voice data of “stretch the knees slowly.wav” illustrated in  FIG. 20 , i.e., a voice record saying “stretch the knees slowly”. By mentioning the names of the user&#39;s bodily parts in this manner, it is possible to lead the user to the target exercise posture (corresponding to the target value) and to draw the user&#39;s attention to the bodily parts at issue. This makes it possible to effectively lead the user to the target exercise posture. 
     Although the feedback stimulus is outputted in the form of a voice according to the foregoing embodiment, the present invention is not limited thereto. For example, the feedback stimulus may be a sound such as background music or the like rather than the voice. As a further alternative, the feedback stimulus may be outputted in the form of an image or the like. For example, as illustrated by dot lines in  FIG. 6 , it may be conceivable to employ a configuration in which the image data pre-stored in an image data storage unit  72  are outputted to an LCD  73  and notified to the user by an LCD driver  71  connected to the control circuit  62 . In addition, it may be conceivable to employ a configuration by which to output a feedback stimulus regarding the change in the operation pattern or operation amount of the seat  13 . For example, as indicated by dot lines in  FIG. 6 , it may be conceivable for the control circuit  62  to control the seat rocking mechanism  12  in such a manner as to reduce the operation speed of the seat  13  or to make the rocking operation angle of the seat  13  substantially horizontal, thereby lessening the exercise load. This may be notified to the user by a voice or through the display of an image or the like. 
     Although not specifically mentioned in the foregoing embodiment, it may be conceivable to employ a configuration by which to output a feedback stimulus together with incidental effects. One example of the incidental effects is to change the sound volume, sound quality, sound pitch and peak frequency of a voice or background music outputted as a feedback stimulus. It is preferred that the degree of these effects varies with the difference between the target value and the detected information (or the representative value S n ). Use of this configuration helps prevent the feedback stimulus from becoming monotonous, which makes it possible to keep the user highly motivated. 
     Although the pressure sensor α and the angle sensor β are used as detector units in the embodiment and modified examples described above, the detector units may include, e.g., an image sensor γ indicated by a dot line in  FIG. 6 . 
     In the foregoing embodiment, the representative value S n  refers to the average value obtained by sampling, for a specified time period, the detected information outputted from the pressure sensor α. However, the present invention is not limited thereto. As an alternative example, the representative value S n  may be a peak value rather than the average value. 
     In the foregoing embodiment, the seat  13  is operated in such a way as to describe the numeral “8”, consequently performing a rocking motion just like horse riding. However, the present invention is not limited thereto. As an alternative example, it may be possible to employ a configuration in which the seat  13  is allowed to make rocking motions only in the back-and-forth direction or the transverse direction. 
     Although the values of the threshold and the target and the like are exemplified in the embodiments described above, but the present invention is not limited thereto. The threshold value and the target value and the like may be varied as necessary. 
     While the invention has been shown and described with respect to the embodiments, it will be understood by those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.